In 1989, twins Gillian and Gayle Blakeney were cast as sisters Caroline and Christina Alessi respectively,[1] after they wrote to the show's producers at Grundy about making an appearance.

[2] The pair almost went to fellow Australian soap Home and Away, but they preferred Neighbours as a programme and they wanted to stay in Melbourne, where it was filmed.

[1] Gillian told Hilary Kingsley of the Daily Mirror that for a joke, she and Gayle swapped places during one scene and no one noticed.

[4] Lorna Cooper of MSN TV also found that Caroline was the more career-minded and confident twin, in contrast to Christina, who was quiet.

[6] Producers created an infidelity storyline which threatened to destroy her sister's marriage to Paul Robinson (Stefan Dennis).

[11] Of her decision to leave, Blakeney stated "While I love the character and I have thoroughly enjoyed myself on the show, I feel it is time to move on as an actor.

[11] Gayle was contracted with the show until July 1992 and was happy to stay for longer, as she felt there would be "plenty of life" for Christina after Caroline leaves.

"[12] Caroline and her sister twin Christina arrive on Ramsay Street under the pseudonym "Linda Giles" after witnessing a murder and rent Number 22 from Paul.

Melanie Pearson (Lucinda Cowden) soon discovers "Linda" is actually two people and the twins eventually reveal the truth to Paul.

On her return to the office, she and Martin Tyrell (Nicholas Bell) bump heads when he mistakes her for a receptionist and they clash.

After Christina gives birth to her and Paul's son Andrew (Shannon Holmes), Caroline and Martin get caught up in the moment and kiss.

Caroline struggles to cope with the guilt and panics when her cousin Marco Alessi (Felice Arena) overhears a conversation between her and Paul about the kiss.

Years later, Caroline attempts to stop Christina from sabotaging Paul and Terese Willis's (Rebekah Elmaloglou) wedding.

Christina soon tells Paul that his ex-wives coming after him was a plot orchestrated by his daughter Elle Robinson (Pippa Black).

Ian Morrison, author of Neighbours: The Official Annual 1992, observed that the twins' arrival "brought glamour to Erinsborough", as well as "a considerable amount of confusion.

"[15] James Cockington from The Sydney Morning Herald branded the story in which Caroline and Christina swap identities to secure a business deal "contrived".

[18] Tony Pratt from the Daily Mirror questioned why Caroline moved abroad in her exit story because the majority of Neighbours characters were simply "exiled" in Queensland.

[19] A writer from The Press and Journal opined that "fans of BBC's Neighbours will be on the edges of their seats for the lunch time session, in which Caroline makes a choice between the two men in her life.

[20] Kate Randall from Heat included Caroline and Christina in the magazine's top ten Neighbours characters of all time feature.