In 2006 she attended the prestigious Sylvia Young Theatre School, she now attends Westcliff High School for Boys Sixth Form.
In 2004 Kirsty appeared on the British Broadcasting Corporation soap opera EastEnders in the Christmas party. She played numerous characters Zoe Slater, (Michelle Ryan), Pauline Fowler, (Wendy Richard) and Pat Butcher, (Pam Street Clement) all in famously well-known sketches, as well as singing and playing onset characters. Hickey also appeared in Ministry Of Mayhem on Independent Television, Granada alongside Holly Willoughby and Stephen Mulhern.
She played mini Polly with her trolley with Holly as the older Polly, where they both hosted the game of Cakey Sk8 with celebrities.
The rules of the game were that, they propel cakes from skateboards, and the cake which reaches highest up on the wall wins. That week Kirsty met Girls Aloud.
lieutenant was aired live in November 2005. She was interviewed on Richard & Judy about Harry Potter and the Deathly Hallows part one in 2006.
She appeared on The X Factor singing and dancing alongside Rhydian Roberts, Same Difference, and the previous year Leona Lewis.
On 13 February 2011, Kirsty appeared on Got To Dance with the England tap team, Tap Attack. The team got down to the final 28 acts but did not go through to the finals. In September 2009, Kirsty filmed The Long Lonely Walk directed by Leon Chambers acting alongside Jeremy Sheffield, Sylvia Syms and Tessa Peake-Jones.
In 2005, Kirsty appeared in Billy Elliot at the Victoria Palace Theatre, as the youngest ballet girl, Alison Summers, she performed with Haydn Gwynne, Alex Delamere and Chris Lennon.
She then went back two years later and portrayed an older character. In 2007, Kirsty then went into Fiddler On The Roof playing Bielke, at the Savoy Theatre, working closely with Henry Goodman.
Kirsty is the voice of Annie in Little Einsteins on Playhouse Disney. She also undertakes Language and Singing Tapes for Oxford University Press, Oxford, UK and Cambridge University.
She also has taken part in many caberats, performing in front of people such as Bruce Forsyth and The Princess Royal, in aid of raising monies for Save the Children.
On 18 September 2010, Kirsty performed in front of Pope Benedict XVI at Hyde Park, London to raise money for CAFOD.