Finlay first appears as a runaway who unsuccessfully attempts to get a free meal from the Diner and sleeps at the boat shed. She spends the night on one of the boats but wakes up to find it has been taken out by Nick Parrish (Bruce Roberts) and Lucinda Croft (Dee Smart). When they discover her, Lou gives her money to stay at the caravan park. She befriends Sophie Simpson (Rebekah Elmaloglou) and tells her of her plan to support herself through school. Sophie helps persuade Ailsa Stewart (Judy Nunn and Bobby Simpson (Nicolle Dickson) to give her a job at the Diner. Finlay applies to Summer Bay High but the new principal Lois Crawford (Tina Bursill) is trying to turn the school into a more elite establishment and doesn't want Finlay attending. Donald Fisher (Norman Coburn), who has been demoted in favour of Lois, champions her cause. When Fin accidentally hits herself with a cupboard door, she uses the bruise to claim Lois hit her. The lie is found out but Lois is removed from the school anyway and Donald is reinstated as principal. Finlay is set a test, which she passes at the second attempt and she is enrolled in Year 11. As part of a deal she had earlier made with them, Finlay moves in with Sophie's foster parents Michael (Dennis Coard) and Pippa Ross (Debra Lawrance. Donald checks her records and learns that her mother Irene (Jacqui Phillips) has reported her missing, meaning he is obliged to tell the police where she is. Irene is revealed to be a violent alcoholic but Finlay almost returns to her when Irene attempts to use her younger brother Damian (Matt Doran) as leverage. However, Damian tells Finlay to keep her new life and Finlay tells him he should make the break from Irene as well.
Fin discovers Sophie is pregnant by her late boyfriend David Croft (Guy Pearce). When Sophie starts dating Simon Fitzgerald (Richard Norton), Fin betrays her confidence and tells him about the pregnancy. Finlay makes friends with Meg Bowman and is upset by her death from leukaemia. She dates Randy Evans (Murray Bartlett), who Michael disapproves of. When she asks to go away with him and his friends for the weekend, Michael refuses and although he agrees to let her spend the day with them, he tells her if she stays overnight she will not be welcome in the house. Fin's evening is a disaster when Randy gets drunk and allows one of his friends to make advances on her. She returns to Summer Bay but doesn't feel able to go back to the Rosses so she stays with Bobby and her boyfriend Greg Marshall (Ross Newton) until Bobby and Randy convince her to return home, where Michael and Pippa offer to officially foster Finlay. She is initially keen but feels guilty when she gets a letter from Damian, who runs away from home. Fin and Sophie hide him until he is discovered but he is allowed to stay with the Rosses when Irene is revealed to have been beating him. Irene tries to take Damian by force and falls down some stairs during a confrontation. She threatens to charge Fin and Damian with assault if they do not come home but ultimately accepts defeat and both Finlay and Damian are fostered by the Rosses.
Finlay worries when Damian becomes friends with Shane Parrish (Dieter Brummer) who leads him astray. She initially believes Damian is behind a robbery at the surf club kiosk but when she learns Shane is responsible and is blackmailing Damian she defends him to Adam Cameron (Mat Stevenson). She later shares a kiss with her friend Blake Dean and assumes they are now a couple. Blake isn't keen but can't bring himself to tell her, so he and Adam arrange for Finlay to see him kissing another girl, Andrea. When Fin learns it was a set-up, she gets her own back by sabotaging Blake's alarm clock so he is late for an exam. She later has a relationship with classmate Robert Davis (Steven Trinder) and tries to set Sophie, now a new mother, up with his friend Gary (Grant Wilson) but Sophie decides she isn't ready for a relationship. Fin has a crisis when Sophie and Ryan Lee (Alistair McDougall) accidentally throw her study notes away. She tries to use Blake's instead but is unable to make sense of them. Robert gets some stolen exam papers so they can cheat but Fin has an attack of conscience and confesses to Nick, meaning she has to repeat the year.
Fin and Blake begin scuba diving lessons together and become close again. Fin's reluctance to commit to a relationship with Blake fades after an accident where she is trapped underwater and nearly drowns. They share a kiss and become a couple. Irene (now played by Lynne McGranger) returns to town, having sobered up, but Fin and Damian are reluctant to trust her, trying to hide all the alcohol in the house and refusing to return to live with her. Blake's sister Karen (Belinda Jarrett) is paroled from juvenile detention and begins causing problems. After she starts a fight in a night club that results in Blake being punched, Blake follows Karen to the city to sort her out and later sends a letter to Fin saying he is not coming back, leaving her heartbroken. Irene moves to town permanently and, although Fin declines to live with her, they begin to rebuild a relationship, with Irene helping Fin when she begins taking medication to help her study. Fin is less pleased when her older brother Nathan (David Dixon) appears after being released from jail and is proved right when Nathan goes back to his old ways and is jailed for robbery. Michael's son Haydn (Andrew Hill) returns to town and Fin dates him until it is revealed he has a gambling addiction and he temporarily flees town after conning money out of Michael and Pippa. When he returns and tries to mend his ways, Roxanne Miller (Lisa Lackey) convinces Finlay to give Haydn another chance. Haydn convinces Fin to help him with a plan to win enough money to pay Michael and Pippa back but his horse loses. Haydn then leaves town again, leaving a goodbye letter. Not long after, Fin leaves Summer Bay to attend college.
Two years later, Fin returns to Summer Bay. She explains that she has been told she cannot have children as she miscarried six months earlier. She also admits that Barry, (David E Woodley) her boyfriend, proposed to her. She tells Irene that they would like her to be a surrogate and she accepts. They leave for the United States to start the procedure. A few months later Finlay herself falls pregnant, but assures Irene she will bring up both babies. She returns to town to be with Irene when she gives birth, but her son Paul is abducted only a few hours later. A distraught Irene tells Fin that Paul is nothing to do with her and orders her to go.
Later, Fin and Irene reconcile off screen when Irene visits her after the birth of her other son Mark. Soon after, Irene is reunited with Paul and sends him to live with Fin.
