Gillian began acting at school and at the Liverpool Everyman Youth Theatre. Whilst attending, as a fourteen-year-old in 1986, she landed the role of Damon Grant's girlfriend, Debbie McGrath, in Brookside (1982). The character was originally intended to appear in just three episodes, but Debbie proved to very popular and the part went on to last for more than a year. It also led to the spin-off mini-series Damon and Debbie (1987). Gillian passed nine GCSEs at school and stayed on to take A-levels in English, French, History and General Studies. Whilst appearing on stage in plays including "Othello" and "School for Scandal", she decided she wanted to 'do it properly'.
