Chloe is delivered by Mo Harris on October 26, 2000. Fifteen-year-old Sonia Jackson did not know she was pregnant. Chloe is the result of an under-age fling between Sonia and Martin Fowler and she is subsequently given up for adoption to Neil and Sue Miller. The Millers change Chloe's name from "Chloe Jackson" to "Rebecca Chloe Miller".
In 2002, Sonia (who suffered from depression over the guilt of abandoning her daughter), kidnaps Rebecca and barricades herself inside her house. Neil and Sue (now Victoria Willing), understandably upset about Sonia's actions, give Dot Branning, fifteen minutes to persuade Sonia to give Rebecca back before they phone the police. Dot successfully persuades Sonia to give Rebecca back.
In 2005, Neil and Sue are killed in a car crash and Rebecca moves in with Sue's mother, Margaret Wilson. Sonia reads about the crash in the newspaper and she and Martin, who are now married, are concerned for their daughter and decide to track her down to make sure she is well. Posing as friends of the Millers, Margaret allows the Fowler's into their home and it is only when they admit who they really are that she tells them to leave.
Pauline Fowler, Martin's mother, demands to be part of Bex's life, causing upset. Sonia is furious when she discovers Pauline and Martin have been seeing her daughter behind her back. Eventually, Sonia gives into her urges and grows closer to Bex too. Margaret decides to make Sonia and Martin Rebecca's legal guardians in case anything happens to her, unaware that Sonia and Martin have separated due to Sonia's lesbian adultery. Sonia persuades Martin not to tell Margaret that they have split up, but when the truth comes out, Margaret is furious and refuses to give Sonia guardianship of Bex. When Margaret has a fall and dies, Martin was given custody of Bex and his mother Pauline refuses Sonia access, causing many rows and Bex's name is changed to Rebecca "Bex" Fowler. Sonia and Martin reunite in December 2006. On Christmas Day 2006, Pauline dies just before emigrating to America. Bex saw Sonia slap Pauline before her death and believes that Sonia killed Pauline. Sonia tries to keep Bex quiet, but the truth comes out and Sonia is arrested following a row with Martin.
After absconding with Bex, Sonia is cleared of Pauline's murder when Joe Macer, Pauline's husband, admits to manslaughter. Sonia leaves Walford with Martin and Bex in February 2007. Rebecca returns on January 15, 2014 when when Carol Jackson tells Sonia about her breast cancer. She is seen in October 2014 when Sonia discovers that she has been missing school to practice her guitar for music school with Charlie Cotton. Having arranged for Rebecca to appear at the Queen Vic, Charlie calls Sonia. Rebecca performs a cover song of "You and I" by One Direction. In March 2015, Rebecca, tired of strife between her parents, enters a rebellious phase of her life. She adopts a goth fashion style and insists on being referred to by her former name, Chloe before deciding to stick by a nickname, which is Bex. Bex rejects Sonia as she has been living away from them, and they become further estranged when Martin reveals she is having a lesbian relationship with Tina Carter. After realizing that the situation may be his own fault, Martin decides to have Bex live with Sonia as she needs to spend more time with her mother, although Bex is more close to her father.
Martin starts a relationship with Stacey Branning and moves in with her and her daughter Lily Branning. Martin plans to propose to Stacey and Bex gives him her blessing. Stacey gives birth to a son, Arthur Brian Fowler, although unbeknownst to Martin, Arthur is not his son. When Stacey is diagnosed with and sectioned due to postpartum psychosis, Bex realises Martin is struggling with Arthur, Lily and work, so she draws him up a schedule. She accompanies Martin on a visit to the hospital to see Stacey. When Martin learns the truth about Arthur's paternity, he goes to stay with his sister Michelle Fowler in America and when he returns, he intends to leave for good. Martin then reveals that Kush Kazemi is Arthur's father to everyone in the pub, including Bex. Martin tells Bex that Arthur is still her brother and Bex later explains to Stacey that she hurt her father. When Martin and Stacey get engaged, Martin tells Bex, who says that Arthur really is her brother now. Martin decides to adopt Arthur as he thinks of him as a son.
Bex takes Louise Mitchell to school on her first day and when Louise has a fight, Jay Brown collects her and the girl she had a fight with turns out to be Jay's girlfriend, Linzi Bragg. Bex and Louise tell Jay that Linzi is Bex's friend, Star, and is 14. Linzi gets upset when Jay is adamant things are over and Bex comforts her. Bex tells Linzi's mother, Thelma Bragg, about the relationship, and points out Jay to her when she demands to know who has been having sex with Linzi. Although Jay has not had sex with Linzi, Bex states that Thelma's accusations are true. Jay is arrested and Bex is interviewed by police. After Bex tells Sonia that she has had sex, Sonia, Sharon Mitchell and Honey Mitchell talk to her and Louise about the pressures and consequences of sex, but Bex reveals that she has not had sex. When Sonia finds a lump in her breast, she tells Bex, who fears that Sonia has cancer, but it turns out to be a cyst.
Bex has a crush on newcomer Shakil Kazemi and is jealous when Louise flirts with him. At Martin and Stacey's reception, she & Shakil kiss and they are seen by a jealous Louise. Martin struggles to accept Bex dating and after disputes between Martin and Shakil, Sonia gets them to make amends for Bex's sake. Tina's mother, Sylvie Carter later moves in with Sonia and Tina, but Bex does not cope looking after her when Sonia and Tina are not around. Bex is stunned when Shakil tells her he wants to have sex with her. Bex tells him that she is not ready for sex and she talks about it with Louise, who tells her Shakil will not wait for long. After taking advice from Louise, Bex decides to change her appearance. Bex confides in Stacey about Shakil wanting to have sex, who mentions this to Martin; Martin interrupts Shakil's party, but later apologises to Bex.
Sonia is offered a job in Kettering and Martin and Stacey agree for Bex to live with them. Bex is angry and upset with Sonia and refuses to say goodbye, but Tina arranges for them to talk. Bex is upset and Shakil comforts her. Bex moves in with Martin and Stacey, but struggles to cope with the overcrowding until they move into Sonia's old house. When Bex discovers Shakil has bought condoms, she cancels her 16th birthday party to avoid him. Stacey advises Bex to tell Shakil how she feels. When the pair are alone in Bex's room, she stops him from going further than kissing, so he calls her frigid. However, Shakil apologises to Bex and she forgives him. Bex finds out from Louise and Shakil that people are talking about her relationship and about her and Shakil not having sex. Shakil suggests to Bex they send explicit photos of themselves to each other instead of sex. After talking with Louise and Tina, Bex decides to take an explicit photo. She tells Louise she has not sent the photo and thinks Shakil is not interested in her when he ignores her. Bex confronts Shakil about his ignoring her and Bex admits to Shakil that she did not want to break the law and feared the photos being shared, but apologises for hurting his feelings. Bex then tells Shakil she wants to have sex with him and they try to arrange a place and time that they can be alone. Bex goes round to Shakil's whilst his mother Carmel Kazemi and brother Kush are out and they have sex. Immediately afterwards, Shakil sees Bex and Louise talking and assumes Bex is telling Louise about it, so he ignores Bex and refuses to tell her if they are still together. Bex asks Stacey how to know if you're having sex right and explains how Shakil is behaving towards her.
Bex is upset when Shakil changes his online status to single. An upset Bex tells Stacey she has been dumped, who tells Martin and she is left embarrassed when Martin publicly has a go at Shakil. Martin's aunt and godmother, Kathy Beale tries to justify his actions, but Bex refuses to forgive Martin or Stacey until she watches Shakil kiss Louise as part of the Christmas play. Bex shows Louise a prospectus for a college after deciding she needs a fresh start but decides to stay at her school's 6th form to study A-Levels. Keegan Baker insults Bex and she finds out Shakil was one of the boys who teased Louise with Keegan and warns him to stay away from her. When the school closes early, Bex, Louise, Shakil and Keegan take a bus home, but the driver suffers a heart attack and drives through the market and into the viaduct. The students are trapped but escape through the emergency exit. Bex is upset to learn Martin is trapped under the bus, but everyone works together to get him out. She stops Louise from truanting after being teased over a video posted online by Keegan of the bus crash and Louise gets Bex to promise that she will not resume her relationship with Shakil.
Convinced that Shakil is encouraging Keegan, Louise gets Bex's phone and sends Shakil's naked photo to her friends Alexandra D'Costa & Madison Drake and Bex is left distressed when she finds out what Louise did and that the photo has been sent to another person. Bex remains angry with Louise, Madison and Alexandra for the way they have treated Shakil and is hurt when Shakil tells her she can "drop dead". On Valentine's Day, Bex receives a card and believes Shakil sent it, however, she realises Louise, Madison and Alexandra played a prank on her. Shakil tells Louise that he has seen Bex and Travis together and Madison and Alexandra tell Louise they believe Bex has been after Travis for a while, but when Louise confronts Bex, she insists they are just friends. Bex takes a liking to Preston Cooper, a student from the United States with whom her aunt Michelle had an illegal relationship. Preston encourages Bex to skip school and Preston gets Michelle to Sharon's house, where he is in bed with Bex and Michelle realises Preston is using Bex to make her jealous. After discovering that Bex had sex with Preston, Madison & Alexandra spread the fact, and Keegan & Shakil find out.
Keegan suggests to Shakil they should get revenge on Bex, and Keegan imposes Bex's face on a porn video and spreads it around. Bex is humiliated when Martin sees the video. She and Martin meet with one of Bex's teachers where Bex refuses to name anyone involved and they are told it is being passed onto the police as it is treated as an image of child abuse. Martin is called into school and is informed about Shakil's explicit photo. Bex takes the blame for sending it and she and Martin are told Bex will be interviewed under caution by the police the following day because she has distributed an indecent image of a child. Bex overhears Martin talking negatively about her to Stacey. When she tells that Louise she will admit the truth, Louise confesses that Madison and Alexandra were responsible for sending the photo and she should think about bringing them into it. Bex is cautioned and tells Louise, Madison and Alexandra she took the blame despite being the only innocent person, and they laugh at her.
The police and social services visit Bex, Martin and Stacey to ask about explicit photos Bex took of herself. Although Bex thought she had deleted the photos and had not sent them on, they had been backed up automatically. Bex is told she can return to school, but when Martin returns her phone, she only receives abuse, so she decides to do an apprenticeship, which Martin disagrees with her doing. Kush persuades Bex to return to school and not let what is happening ruin her life. Madison and Alexandra overhear Bex insult them when she confronts Louise over their friendship. While in the toilets, Madison and Alexandra push Bex, tear her shirt and write on her face whilst Louise stands outside, worried about Bex but feeling unable to help. She admits to teachers Mrs Robyn Lund and Mr Gethin Price that Louise, Madison and Alexandra were responsible for her attack and sending the photo, but the girls deny knowledge of either incidents and Bex ends her friendship with Louise, but Linzi offers her support.When Preston returns from Manchester, he and Bex become a couple. Louise finds out that Michelle and Preston are having an affair so tells Bex, who refuses to believe it until she sees Preston touching Michelle and Michelle flinching, so publicly demands to know if Michelle is having sex with her boyfriend. Preston apologises to Bex and admits he loves Michelle. Stacey and Whitney Dean stick up for Bex, ordering Preston to leave. While trying to find Preston, Michelle crashes a car into the chip shop after taking sleeping pills with alcohol. After this, Preston returns to America after being convinced that Michelle does not need him; Bex is glad that he has gone. Michelle tries to make amends with Bex, who reminds Michelle of what she has lost. Bex works alongside Michelle at the café and she snaps at Michelle when Madison and Alexandra make remarks about them and Preston. Bex goes busking but almost backs out when she sees a group of girls laughing. Shakil persuades her to carry on, but she is stopped by Martin. When Alexandra sees Bex in the local shop, she knocks the sugar she is buying out of her hands and sticks chewing gum in her hair when she goes to pick it up.
Later, Bex goes to the café where Kathy asks her to serve Alexandra and Madison their drinks. They insult her and Alexandra trips Bex, causing Kathy to spill soup on Madison. They later warn Bex that she can never escape them, and gain access to Bex's home by telling Stacey they are her friends and they smash her guitar. Bex is then tricked by them into putting mud covered in chocolate in her mouth, which the film and tell her it is cat feces. Bex sees the video of this online and calls Sonia in tears, who returns to Walford and announces that she wants Bex to live with her. Sonia also visits Bex's school but does not mention Louise is part of the bullying when Bex asks her not to, which gives Louise hope that they can be friends again. After Michelle and Sharon get them talking, Louise agrees not to be friends with Alexandra and Madison, but in front of Bex she tells them she is not friends with Bex again, so Bex walks off in anger. Unknown to Louise, Madison and Alexandra plan to take revenge on her because they blame her for being reported to the school. Bex overhears Madison and Alexandra inviting Travis to a party at Louise's home which Louise believes will just be for the three girls. Bex tries to warn Louise that they cannot be trusted but Louise accuses her of being jealous because she has no friends of her own. Travis leaves Louise's party and tells Bex that Louise needs her.
After Louise gets drunk and becomes sick, she staggers outside, coughs up blood and collapses. Panicking, Travis Law-Hughes goes to get Bex and she calls for an ambulance and Louise's step-brother Denny begs them to not let her die. Madison, Alexandra and Keegan start to panic when they realise Louise could die. Louise is taken to the hospital with paralysis and Sharon tells Louise about Bex finding her. When Louise is sent home, she invites Bex round, but Madison and Alexandra turn up, so Bex does not go to Louise's house. After speaking to Denny about the party on Travis's behalf, Bex tells Louise that Alexandra followed Travis into the kitchen and Alexandra interrupts them. Alexandra gets herself out of trouble by telling Louise and Bex that Travis may not have been responsible for spiking her drink and Louise insists that Madison and Alexandra are still her friends. Bex hears a rumour that Louise had sex with Keegan at the party, so she tells her to take a pregnancy test, but Martin catches Bex purchasing the test for Louise and wrongly assumes it is for herself. Bex is delighted when she learns Stacey and Martin are having a baby. Sonia returns from Kettering and wants Bex to move in with her and her brother, Robbie Jackson and Dot Branning, however, Bex wants to remain with Martin and Stacey. Alexandra decides she will take revenge on Bex when she overhears Bex smugly telling Travis that Alexandra will mess up in the showcase.
Before Bex's performance at the showcase, Madison and Alexandra break a guitar string and when Bex looks for one in a classroom, Madison and Alexandra pin Bex up against a wall. Shakil hears the bullying through headphones and exposes it through the soundboard. Bex is found locked in the cupboard and she is encouraged to perform following her ordeal. Bex and Louise make amends and she decides to go the prom with Shakil. At the prom, Louise suffers burns after being pushed onto lit candles by Alexandra and Madison, leading to their arrests and being expelled from school. Bex visits Louise in hospital but her mother, Lisa Fowler says Louise wants no visitors and Lisa tells Bex her plans for Louise if she was well. Louise is distressed when Lisa and Bex arrange for Travis to visit her. Bex receives her GCSE results and is disappointed that she gained a D in music, so Sonia contacts Gethin about Bex's result and Gethin agrees to tutor Bex. Following a gas explosion, Bex tends to Gethin's wounds and they kiss. Bex apologises but Gethin reassures her, however, he says he can no longer tutor her and says a relationship would be illegal due to the fact he is her teacher and insists he has no feelings for her.
Bex attempts to make Gethin jealous by flirting with Shakil and Gethin asks her to stop her behaviour and he later kisses Sonia, watched by Bex. When Bex claims to have a new boyfriend, Gethin starts tutoring her again. Bex continues to pursue him but he insists nothing can happen, and Louise asks Bex not to chase Gethin. However, Bex tries to get Gethin to admit he likes her, but he goes through with telling Sonia that Bex kissed him. Sonia is furious that the kiss happened weeks ago and throws Gethin out. She asks Bex for the whole truth and Bex insists it was just a kiss and asks Sonia not to report Gethin. Gethin gets drunk and Bex's great-uncle, Jack Branning, Gethin's landlord, evicts Gethin when he finds out about the kiss. Gethin then leaves Walford. Louise accidentally tells Shakil about Bex and Gethin, and Bex is heartbroken when she sees Shakil and Louise kiss; though accidental, Louise is stunned and disgusted by Shakil's immature reaction. A couple of months later, Bex's half-sister Hope Fowler is born.
In January 2018, Bex answers the door to her cousin Tiffany Butcher who has ran away from her home at Milton Keenes. The next day, Tiffany's sister Whitney discovers a pregnancy test in the bin belonging to Tiffany. When Whitney confronts Tiffany about it, Tiffany tells her it the test is Bex's but once Whitney tells Tiffany that she's going to tell Bex's dad Martin, Tiff tells Whitney it's hers and it's positive. Desperately wanting to stay in Walford she acts like her mother Bianca (who is Bex's auntie) on the phone and Martin falls for it, immediately Whitney finds out it wasn’t Bianca on the phone she exposes Tiffany and is ready to throw her out because of her lying. Tiffany then lies and says she’s in Walford because her mother wanted to kill her self. As Whitney wants to find out why Tiffany has come to Walford, she asks Bex to take her shopping- much to Tiffany's delight. Bex and Tiffany begin to argue when Tiffany wants to get a taxi into town but Bex tells Tiffany that she has to legs so she should use them. Tiffany replies "you are soooo annoying" and Bex tells her to hurry up. Whitney does some more digging and rings step brother TJ Spraggan to come to Walford so she can ask him what’s going on. TJ tells Whitney that Bianca is on a cruise with her partner Terry Spraggan, his daughter Rosie, Bianca's son Morgan and TJ's daughter Beth but Tiffany refused to go. Whitney waits for Tiffany to come back from shopping so TJ can take her home. However, as soon as Tiffany comes home she recognises TJ's coat and runs away. Everyone desperately looks for Tiffany and Whitney goes out of her mind with worry. Bex tries to phone her and Whitney asks if anyone had seen her. Tiffany actually went to see some boys were way older. The boys ask Tiffany her age and she lies saying she’s 17 when she is actually only 14-years-old. When Tiffany runs away from the boys, they try to chase her and hold her up against a car but Whitney, Martin and Bex arrive just in time and Whitney punches one of the boys and Tiffany hugs her. When they get home, Tiffany explains that she was only aloud not to go on the cruise if TJ looked after her but he didn't and it took him three days to realise she was even missing and when TJ eventually did come back home he started having a "threesome" in the living room. Whitney screams at TJ telling him that Tiffany is 14 years old and throws jam in his face, leaving Bex and Tiffany speechless.
When Stacey cheats on Martin with Bex's great-uncle Max Branning, she takes Lily, Arthur and Hope to Brighton to go and see their grandmother Jean Slater because of Stacey's guilt for being unfaithful, returning after 2 weeks. Martin, being angry at Stacey, chucks her out of the house and tells everyone about Stacey's infidelity. He refuses her access to see her children and barricades himself inside the house with Hope, Arthur, Lily, Bex, Whitney and Tiffany inside; he tells Bex, Whitney and Tiffany that Stacey isn't allowed in the house or anywhere near the kids. The next day, Stacey complains because she isn't able to feed Hope, complaining on the phone to her cousin Kat. Stacey decides to sit on the bench outside the house and won't move until she sees her children. After another day, Bex goes outside to confront Stacey, explaining that she isn't needed as they've got it all under control and Whitney and Tiffany are doing a great job. However, whilst this is happening, Lily goes upstairs to try to comfort a crying Hope. She realises that she is hungry and hears her mother outside of the open window. Lily, holding Hope, leans out of the window and calls to Stacey. Stacey and Bex run to underneath the window after banging on the door for Martin, Whitney or Tiffany. Lily tells Stacey, not understanding that Martin has locked her out, that Hope is hungry and that she wants her. Martin hears commotion coming from the front door where a group of people are stood under the window waiting to catch Lily and Hope if they fall. Martin runs upstairs and tells Lily that they are going to see Stacey downstairs. Martin carries Hope downstairs to see Stacey. Stacey then runs to Lily and hugs her and grabbes Hope from Martin and Tiffany runs to stand next to Bex. Stacey is glad her daughters are safe. After feeding Hope on the bench outside, Martin tells Stacey that he is coping and that him, Bex, Whitney and Tiffany have it under control, which she argues due to the events that had unfolded during his first day of looking after all of the kids, and he takes Hope back inside, locking Stacey out again and Tiffany sits on the stairs and watches.
When Karen Taylor tells Sonia and Sharon that she thinks her neighbour Ted Murray is inappropriately touching her daughter Bernadette, she invites Bex and Tiffany round to take her out the house for a bit to get her mind off chess but she refers to them as "the ginger one and the one with the annoying mother". When Bex leaves the room, Tiffany then tells Bernadette that she doesn't talk much and Bernadette replies " it's hard to get a word in over you two". Tiffany then tells Bernadette that Bex is her cousin and she's forced to like her - which makes Bernadette laugh. Bex's best friend and Sharon's stepdaughter, Louise Mitchell, then arrives and brings a doll so Bernadette can "point" to where Ted has touched her. Bex and Tiffany just look at each other and Bernadette leaves the room. When Louise asks Bernadette where she is going, she replies "to the toilet, or do I have to ask your permission to go there an all?".
In May 2018, Bex is left devastated when Shakil dies – having been stabbed by gang member Bruno after attempting to return a bike that Keegan had stolen. Keegan was also stabbed but survived. Flowers and cards are placed on a bench near where Shakil was found in memory of him were Keegan, Bex, Louise, Tiffany, Bernadette and Louise's boyfriend Hunter gather round and remember Shakil. Keegan becomes upset but Bernadette tells him it wasn't his fault. Keegan tells the group that Shakil wouldn't have wanted flowers or cards - he would’ve wanted a good party. Hunter tells them he has spare keys to E20 which his mum runs so they all get drunk and play Truth or Dare. They spin a bottle and it lands Tiffany kissing Bernadette. Tiffany tells the group that she won’t kiss Bernadette but Hunter dares her to do it - so Tiffany kisses Bernadette, leaving everyone gobsmacked and she replies "#NeverDareAButcher". Keegan then grabs the bottle and spins it round, hoping it will land on him so he can kiss Tiffany. It lands on Keegan and he leans in to kiss Tiffany, the pair snog and smile at each other but Bernadette doesn't like the thought of her best friend and her brother kissing. Louise also appears to be jealous, even though she is going out with Hunter. After that, everyone makes a toast to Shakil. The next morning, Tiffany thinks that she is ill, but Bernadette reminds her that it’s a hangover.
The following year, overwhelmed by the prospect of going to Oxford, Bex takes drugs to cope with her exams and runs away; she is found by Stuart Highway (Ricky Champ). On the night of her leaving party, Bex writes a suicide note to her parents and attempts to overdose on pills. The following morning, Sonia finds her unresponsive in bed.