Libby is the second child born to Denise Fox. Her father, Owen Turner, was an abusive alcoholic; Denise left him and restricted his access to Libby. Libby secretly contacts her father, and he starts making demands to see her. Denise is reluctant to allow this, but Owen appears to have changed, and Libby is keen for her parents to get back together; Denise is swayed and sleeps with Owen. However, as soon as Owen begins drinking again, he becomes abusive and hits Denise. He is arrested, but Libby persuades Denise to give him a glowing character witness statement at his trial, and he is released. Owen kidnaps Libby and takes her to Epping Forest. He drugs her and tries to kill himself and Libby by filling the car with noxious exhaust fumes. She escapes, but he catches her and tries to drown her in a stream. Denise arrives to find Libby's unconscious body on the bank of the stream. She is taken to hospital and makes a full recovery. Owen is imprisoned.
Libby gets involved in various scams with her friend Darren Miller. She develops a crush on Gus Smith, but is too young to be noticed by him, so she begins using an internet chat room, talking to a stranger named "Einstein27". She refuses to listen to Yolande Trueman's concerns about the dangers of meeting someone online and agrees to meet him in person. When she meets the stranger, she discovers that she has been chatting to Darren all along. He admits to liking Libby. She is initially unimpressed, but after Yolande arranges a meal between them, they decide to start a relationship. A few weeks later Darren visits his family in the Cotswolds, and Libby is heartbroken to discover he has decided not to return. She concentrates on her school work and achieves eleven good GCSE grades.
Darren returns some weeks later but Libby avoids him. When she finally plucks up the courage to see him, she hears him talking about someone called Clara. Thinking he has found someone new, she pretends she is going out with Tamwar Masood. It turns out Clara is a dog and the pair get back together. Libby and Darren have an anniversary dinner to celebrate a year of dating. However, Jay Brown reveals that Darren frequently looks at pornography. Libby becomes furious and confides in Tamwar with whom she is in the process of starting a home tutoring business. Darren becomes jealous, but eventually reconciles with Libby and begins thinking about starting a sexual relationship with Libby. He invites her round to do this, however Jay ruins the night by telling Libby that Darren told him that she was a virgin. Libby is devastated, but she eventually comes round and she and Darren decide not to rush things.
Libby achieves A grades in her AS Level exams, leading Denise to declare that she will be applying for Oxford or Cambridge University. Libby worries her mother cannot afford to send her there. She later finds out she has conditionally been accepted at Oxford. Libby turns eighteen and Owen, who is still in prison, contacts her by sending her a birthday card and asking Libby's grandmother, Liz Turner, to arrange a meeting. At the same time, Libby decides it is the right time for her to lose her virginity with Darren. She then phones her grandmother and agrees to meet with her father. Chelsea returns for Libby's birthday and sees Liz in the Square. Libby is forced to reveal that she visited Owen and that he will be released in a matter of months. Denise visits him but then tells Libby he will not be returning to their lives. Libby discovers she will attend Oxford University when she gets the A Level grades she needs but decides against it, saying her mother needs her in Walford. She later changes her mind, and leaves for Oxford early in October. Adam Best, an Oxford student who has taken a liking to her, sends her a text message saying "See you in Oxford. X".
When Owen is released from prison, he returns to Walford to see Libby, although he is not supposed to. Patrick Trueman discovers this and threatens to call the police, but instead he contacts Libby, who comes straight to Walford from Oxford to see her father. She overhears Darren booking a table for two in a restaurant and suspects he is meeting another woman. She turns up at the restaurant and finds Darren there with Owen. Darren says he wanted to ask Owen's permission to ask Libby to marry him. Libby accepts his proposal. When Lucas, Denise's boyfriend and Chelsea's father, has Owen arrested for breaching his bail conditions, Libby at first doesn't believe Owen's claims but is shocked when Lucas confesses. Though angry with Lucas at first she eventually forgives him. Libby makes her dad promise to leave Denise and Lucas alone. The day before the wedding, Owen crashes Denise's hen night to warn her that Lucas killed his ex-wife Trina Johnson and she is in danger.
Both Denise and Libby are angry with Owen. Owen is heartbroken and prepared to leave until Chelsea tells him about the bracelet. Unknown to everyone but Lucas, Owen hides in Phil's Jaguar and confronts Lucas about his crime, leading to Lucas strangling him to death and burying him in the gardens in Albert Square. Libby feels a bit guilty about parting on bad terms with her father but Liz reassures her. Darren receives a card from Heather Trott, which Libby opens and finds cash inside. Libby asks him about it and he says before Christmas he found Heather crying because she could not afford to buy any presents for her baby son George Trott and he felt sorry for her. Libby calls him a softie, but later overhears Heather and her friend Shirley Carter discussing Darren and the paternity of the baby. Libby reveals that Darren is George's father in front of everyone at Syed Masood and Amira Shah's wedding.
Darren tries to speak to Libby but Chelsea will not let him in. He continues to bang on the door while Denise tells Libby that she could go back to Oxford early and it is time to move on. Libby eventually talks to Darren, who explains why he slept with Heather and what happened between them. Libby then talks to Heather who says it was her fault it happened and she did not say anything as she did not want to hurt Libby. Libby then decides to leave and Darren stops her at the tube station and tells her how much he loves her, but she goes anyway. She returns from Oxford and tells her family she is now dating Adam, though Adam tells Darren that Libby she makes up for her lack of good looks by being good in bed. On hearing that Owen has supposedly sent flowers to Liz, Libby wonders why he won't get in touch with her. She steals some CCTV footage from the florists and is shocked to see Lucas ordering a huge bunch of lilies. Lucas explains to Libby that he sent Liz the flowers to buy Owen time because he is drinking again. Libby accepts this and hugs Lucas.
Libby goes back to university but returns when she learns that Jordan is in a coma. She hears Ben Mitchell confess in the middle of the cafe that he hit Jordan with a spanner and tells Lucas this. Lucas locks himself in the community centre and breaks down, blaming Jordan's condition on his own actions. Libby is worried about Lucas's state of mind and tries to coax him to come out. When she threatens to call the police, Lucas finally unlocks the doors. Lucas goes to the hospital and finds Jordan has been awoken from his coma and is safe. Libby tells Chelsea and Denise about Lucas's breakdown. Chelsea accuses her of making a mountain out of a molehill, Denise however listens intently.
Libby is devastated to learn that a body discovered buried in the Square is that of her father. After speaking to Liz, Libby disowns her as she called the police to say she thought Denise was capable of murdering Owen, and she was taken away for questioning. When Adam brings Libby flowers and says Owen must have been murdered for a reason, Libby shouts at him for patronizing her. Chelsea tells Libby that Lucas found Trina's bracelet in Denise's bag after she died, leading them to believe that Denise may have killed both Trina and Owen. They see Denise driving away from the Square alone, and receive a text message from her saying "I'm sorry". In reality, Lucas had killed Owen and confessed to Denise, taken her to a canal and strangled her, sending the text message before throwing the phone in the canal. Libby is the only person who believes that there is no way Denise could have done this and says that "sorry" could mean anything. However, the police tell the family that Denise's car has been found by the canal, before a body is pulled from the water. Libby vows to carry on as normal, but says that this is not like Denise. The police arrive and say they have found a body in the canal along with Denise's mobile. Libby and Patrick comfort each other while Lucas and Chelsea go to the mortuary, where Lucas identifies the body as Denise.
Libby discovers that Adam has been blackmailing Lucy Beale for sex, and dumps him after slapping him across the face, leading to him leaving Walford. She feels let down by Patrick when he does not write a eulogy for Denise, and then asks the family to leave after Denise's funeral, however, Lucas convinces him to change his mind. On the day of Denise's funeral, Libby again questions who she was. Libby is happy when Patrick gives a eulogy to Denise, but is upset when an argument starts between Liz and Denises's sisters Kim Fox and Daphne Fox. Patrick reveals that the girls can continue to stay with him and Chelsea and Libby agree to start packing up Denise's belongings. While celebrating Libby's birthday, Denise walks in, revealing that she is not dead but that Lucas has been keeping her prisoner, and that he was the one who killed Trina and Owen. Lucas enters and confirms this, and takes the family hostage, but when Jordan arrives, they escape and Lucas is arrested. Denise is taken to hospital, and Libby has to go through the pain of attending her father's funeral. Chelsea then decides she wants to move to Spain with Liz, so Libby arranges to take time off from university to help with her mother at home. Denise disapproves of this, and arranges for Libby to go to Spain for a holiday with Chelsea and her grandmother, before returning permanently to Oxford. After tearfully saying goodbye to her family, the taxi is stopped by Darren who is upset that Libby is leaving without saying goodbye to him. Libby says that she has always loved him and that he will always be her best friend, before she leaves Walford. Darren moves away from Walford in 2011, following his break-up with Jodie Gold and opts to stay with Libby in Oxford. A few months later, Jodie also moves to Oxford to be with Darren.
In April 2014, Denise goes to visit Libby at Oxford and she is concerned, as Denise does not like talking about her home life. Later on, Libby calmly confronts Denise, who reveals to a stunned Libby that she does not want to marry her fiancé, Ian Beale. Denise later rings Libby, telling her that she will end her relationship with Ian the following day. However, Ian's daughter and Libby's old friend, Lucy, dies in mysterious circumstances that night and after hearing about her death, Libby sends her condolences to Ian, via a text message to Denise. Libby returns to Walford a few weeks later, in order to attend Lucy's funeral.
She is unhappy when she witnesses how Ian treats Denise and urges her mother to call things off with him. After staying the night at Patrick's, Libby asks Denise to go to Málaga, Spain, with her for Chelsea's birthday. Denise is unsure, but Ian encourages her to go, admitting that he has taken her for granted. Denise and Libby then depart in a taxi and Denise tells Ian that she will be back in a few weeks. On Denise's return, things are a lot better between her and Ian and they later go to visit Libby for the weekend.
Libby returns for her 24th birthday to find Denise arguing with Claudette Hubbard over the preparation of food for the party. Libby opens her presents then receives a secret phone call from Chelsea, and she promises to tell Denise something when she finds the right time. However, Libby cannot bring herself to tell Denise and later calls Chelsea to tell her this. Libby then leaves and returns to Oxford. She returns again in December 2015 for the housewarming party of Kim and her husband Vincent Hubbard, where she reveals to Denise about how troublesome Jordan has become and how he caused trouble for her and Chelsea in Spain.
Libby returns again for Mother's Day and goes for a family dinner, where later she finds a note Denise put there saying that Lucas plans to escape prison. Libby leaves and tells Masood, who advises her to call the police and he helps her get into Denise's house, which has been locked by Jordan Johnson, who is helping Lucas escape. Libby witnesses Jordan raging at Denise and reveals that she has reported him to the police. Jordan becomes angry with Denise and Libby and is arrested. Libby then returns to Oxford after saying goodbye to Denise and Patrick.
In April 2016, Libby returns upset, and tells Denise she is pregnant. Denise is overjoyed but Libby says she is having an abortion and has already taken the first of two abortion pills. Denise is against this and she gets very drunk, with only Kim supporting Libby's decision. The following day, as Libby returns to the abortion clinic to terminate her pregnancy, a hungover Denise arrives to support her alongside Kim. She then thanks Denise for being a good mother to her before leaving again. Libby returns in November after Kim calls her and is shocked to see that Denise is seven months pregnant. She vows to remain in Walford and help Denise with the birth. Denise is frustrated when Libby insists that Denise should eat only vegan food. After Denise is suspended from her job, Libby helps her get it back by threatening legal action. However, Denise tells Libby that she should not be sacrificing her life in Oxford for her, so after sharing an emotional farewell with Denise, Libby departs. Libby returns with Kim and her grandmother, Emerald Fox, for the birth of her half-brother. Libby is shocked when she learns Denise is having her son adopted, but respects her decision.
In September 2018, it is mentioned that Libby is the only student from Walford High to ever attend Oxbridge.