Before her on-screen appearance, Tanya lived on a council estate with her mother Cora, sister Rainie and her father. In her teenage years, her father was diagnosed with cancer and Tanya was often the one to look after her ill father. It was revealed in 2011 that Tanya had helped her father to die, with everyone previously thinking he had died a peaceful death. At a young age Tanya was also involved with alcohol and drugs. Tanya engaged in an affair with married man, Max Branning. Although Tanya has claimed she didn't know he was married, 18 year old Tanya fell pregnant with her first child, Lauren. Max left his wife Rachel and young son Bradley to be with Tanya and his daughter Lauren, who was born in March 1994. Max and Tanya then married in August 1994. Tanya later had another daughter, Abi, who was born in 1996.
Tanya arrives in Albert Square after her husband Max Branning's car breaks down, not realising in fact Max is visiting his family. She finds out that he has had an affair with Gemma Clewes but forgives him. To make it up to her, Max buys 10 Turpin Road for Tanya, which she turns into a beauty salon named Booty. Tanya, after much pressure from Max, gives birth to Oscar. Unbeknown to Tanya, Max has started an affair with Stacey Slater, who is Max's son, Bradley's former girlfriend. When the affair is revealed on Christmas Day on a video recording recorded by Tanya and Max's daughter, Lauren Branning, Tanya asks for a divorce and starts a relationship with Stacey's brother Sean Slater. Tanya plots to bury Max alive and with the help of Sean, they drug Max and bury him in the woods. Tanya later feels guilty and digs him up and breaks up with Sean. Tanya then has to face her sister, Rainie, turning up as she did the year before, claiming she is clean of drugs, though tests are positive, so Tanya orders her to leave. Tanya then starts a relationship with Max's brother Jack Branning and Max tries to split them up. Tanya and Max later share a kiss, after Max is abducted and beaten by Jack. Max is knocked down in a deliberate hit-and-run. Tanya admits to the police that she tried to kill Max; however, Lauren was the real culprit. After the police find out Lauren was the driver, Max and Tanya suffer a bumpy relationship which ends up in Tanya forgiving Max and allowing him to move back in, but when she finds out they are in debt and Max has been hiding it, she leaves with Lauren and Oscar after finding out Booty was to close down, with daughter Abi refusing to go with Tanya and staying with Max.
Tanya returns to Walford with her new fiancé Greg Jessop. Tanya's mother, Cora and Rainie arrive in Walford for her wedding, much to Tanya's dismay. Greg and Tanya marry, and Tanya soon starts an affair with Max. Greg later buys the beauty salon from Roxy Mitchell and later pushes Tanya to have another baby, though Tanya is against the idea. Tanya allows Rainie and Cora to move in. Tanya and Max plan to reveal their affair but Tanya finds out that she may have cervical cancer. After discovering this, she breaks up with Max, but he decides to tell the truth to his fiancé, Vanessa Gold who reveals all to Greg. Heartbroken, Greg leaves Walford and when Max realises Tanya does not want to be with him either, he leaves too. Tanya is diagnosed with cervical cancer and tells only Lauren and forbids her from telling anyone else. Greg briefly returns but cannot handle the news that Tanya has cancer and quickly leaves again. Tanya then decides to stop her therapy, although does not tell Lauren about this. Later, Tanya agrees to allow Cora to move back in, after she has been thrown out by Dot Branning. Tanya's doctor, Yusef Khan, later confronts Tanya and asks why she has stopped her treatment. Tanya goes to the hospital where she tells her doctor that wants no more treatment as she does not have the strength to fight, despite the fact she could die.
Max returns to Walford with his brother Derek Branning. Max insults Tanya, and Tanya throws him out. As Tanya starts to throw her mother and sister out, Lauren reveals that Tanya has cancer and confronts her about stopping her therapy. Tanya then tells Cora and Rainie the truth about how her father died – he did not die peacefully as they believed, but was in constant pain and so Tanya helped him to die. Max then reconciles with Tanya and they become a couple again. She learns that she has been given the all-clear from cancer but is worried that it might return. She finds it difficult to be close to Max, but after a frank discussion over their marriage and sex life, Max reassures Tanya that she is all that matters to him. When Derek discovers that Tanya scared his daughter Alice Branning away, he threatens to kill Tanya if she does it again. When Tanya discovers that cars at the car lot are being repossessed, she and Max argue, which leads to passion and they have sex for the first time since Tanya's all-clear from cancer. Tanya announces that her divorce from Greg will soon be finalised and proposes to Max. Lauren tells Tanya that Derek stole from Lucy Beale and she confronts him about it. Derek in response taunts Tanya about what he and Max did in Manchester. She confronts Max, who says he was involved in criminal dealings causing someone to get hurt. He then accepts her proposal from earlier and they get engaged.
Tanya discovers a birth certificate for a sister called Ava Anderton. She confronts Cora, who refuses to talk about it, but eventually tells Tanya that Ava died not long after her birth and it hurt so much she never told anyone, not even the father. Tanya then tells Cora that she can talk to her any time. When Ian Beale goes missing, Tanya helps to bring him back to Walford, which makes her decide she wants Rainie at her wedding, but Cora lies to her that Rainie does not want to attend, when in fact Rainie does not want to see Cora. Patrick tells Tanya the truth about Ava – that she is alive and Cora gave her up for adoption, so Tanya secretly tracks down Ava to her place of work, a school in Dalston. Tanya is shocked that Ava is mixed-race, and decides not to see her again. Tanya leaves her purse behind and Ava returns in, meeting Cora. Cora is shocked when Ava says her name, and is angry at Tanya, disowning her.
Lauren is involved in a car crash and tells Tanya that she is in love with her cousin, Joey Branning. Derek blackmails Tanya to keep Lauren and Joey's relationship secret from the rest of the family, and Joey is forced by Derek to end his relationship with Lauren. On Christmas Day, Tanya is stunned when Max's secret wife, Kirsty, arrives moments before she is due to remarry Max. Max insists he thought they were divorced and Tanya and Max continue their relationship, but when Tanya finds Kirsty's keys in Max's pocket, Tanya assumes Kirsty and Max are still involved. She tells Kirsty to sign divorce papers, but Kirsty refuses. Lauren also discovers that Tanya has not attended a hospital appointment, when Tanya said she was given the all-clear from cancer. Kirsty agrees to the divorce, realising she is hurting Max, and Max shows Tanya saying Kirsty is leaving. Tanya realises Max still loves Kirsty because he refuses to have sex with her and is sad about Kirsty leaving. Max confirms this so Tanya ejects Max from the house saying their relationship is over for good, and she celebrates the break-up. She does not cope though, and is nearly drawn back to Max. She decides that to resist temptation she must leave Walford, and Max is deeply disappointed.
She returns a few weeks later to find Max, Kirsty, Abi and Lauren having a meal together and laughing. Lauren continues to drink but Tanya refuses to believe she is addicted until she keeps Lauren in the house and she reveals that she has been sipping vodka from a water bottle. Tanya locks Lauren in the house but she escapes through the upstairs window. Later, Lauren gets drunk on a night out and leaves with a stranger; she does not return the next morning. Eventually, when she does come back, her skin and eyes are yellow and she collapses in pain. She is taken to hospital where Tanya and Max are told she is an alcoholic, has alcoholic hepatitis, and one more drink could kill her. The doctor suggests that the best treatment for Lauren is residential care. Later, Lauren tells her family that she cannot stand her parents' constant arguing, so Tanya decides to take Lauren, Abi and Oscar to Exeter, where Lauren can get help for her alcoholism. Abi refuses to leave so Tanya leaves Walford with Lauren and Oscar in a taxi, after telling a heartbroken Max she will always love him. Lauren soon returns to Albert Square, but Tanya and Oscar remain in Exeter. In January 2014, Tanya's friend, Jane Beale, reveals to Max that Tanya is now in a relationship, with a man named Tim and that they are planning on getting engaged.
In February 2015, Tanya returns to Walford, to attend Ian and Jane's wedding and after the reception, she agrees to sit and have a conversation with Max. During the conversation, she reveals that she is taking part in a fashion course in Manchester and asks Max if Oscar can move in with him for a while, as he would be stuck with a nanny most of the time if he went with her, due to Tanya's commitment to the course. Before leaving, Tanya admits that she was thinking of rebuilding her relationship with Max, but Jane assures her that that would have been one of the biggest mistakes of her life. Max is falsely accused of the murder of Lucy in July 2015 and after he is arrested, Oscar is sent back to live with Tanya, who denies Max any contact with his son, although Max is later released after Bobby Beale confesses to the crime.
Tanya agrees to let Max see Oscar for his birthday but Cora turns up instead and tells Max that she has told Tanya all about his work with Weyland and that she is not allowing Max to see Oscar. Tanya returns on Christmas Day to take Lauren and Abi away from Walford, informing Ian and his mother, Kathy Beale, that Lauren is moving to Glasgow with her boyfriend, Josh Hemmings. Tanya goes to collect Abi and confronts Max over his recent behaviour and is disgusted that Max and Stacey have resumed their affair and spoke up so that Martin could hear that his wife is having an affair with the same man that she did 10 years ago. When Stacey defends Max, Tanya tells Stacey that Jane has told her that he killed Steven Beale and tried to kill Jane. Abi overhears this and tells Lauren. As they prepare to leave, they see Max on the roof of The Queen Vic and Lauren and Abi attempt to talk him down. Max agrees to come down but Lauren and Abi slip and fall off the roof. Tanya accompanies them to the hospital, where Lauren undergoes surgery whilst Abi has a CT scan. Tanya initially accepts Max's comfort but then pushes him away. They are then told that Abi has suffered critical brain damage and remains in a coma. Tanya is devastated and leaves the hospital in tears.
A few days later, she plans to visit Lauren and Abi with Cora, but Cora comes alone and slaps Max, blaming him for his daughters' injuries. She later learns that Abi is brain-dead and that she will never recover. Tanya avoids being around Max in the hospital and when Abi's life support is due to be withdrawn, Max asks if it can be withdrawn at Abi's time of birth. Cora tells Max that Tanya does not want him present. Max finds Tanya in the hospital's chapel, who is angry with Max that Abi has to die because of him, and agrees to stay away. At the last minute, however, Tanya requests Max to be there when the life support is withdrawn. Before Abi's funeral, Tanya's friends talk about her being unable to attend the funeral as she has had a nervous breakdown. Lauren lies to Max that the funeral has already taken place, but later admits that Tanya does not want him there. On the day of the funeral, Cora yells at Max, urging him to stay away as he has done enough damage to his family, and mentions that she had to sedate a grief-stricken Tanya to get her into the car to go to the funeral. Tanya arrives at the church with Cora, but is unable to get out and tells Lauren that she feels like she has failed as a mother. Lauren reassures Tanya it is fine for her to miss the service as Abi loved her and at the end; Tanya says goodbye to Lauren. Months later, it emerged from Cora that Tanya had to be committed to a psychiatric hospital because of the increasing trauma of losing Abi.
A year later, Max decide to visit her where she forgive him for his actions, knowing that it will be Ian's son Bobby's fault that caused his ruined relationship with their daughters.