This web chat has now finished but you can see all the questions posed to Rachel and her answers in the transcript, below.
Rachel first got a taste for performance aged nine, when she started singing with her dad around the local cabaret circuit in Belfast.
She went onto study singing, acting and dance at the Belfast Institute of Further and Higher Education. Her first paid role was as Maureen in the musical Rent, which came to Ireland to cast a mainly Irish company.
Rachel then landed a place on a one-year postgraduate course in musical theatre at the Royal Academy of Music in London. Before long she was on her first UK tour in a 10 month contract with musical The Full Monty, followed by six months on the road with Tommy and another six months with Tonight's the Night. She also performed original plays and shows at the Lyric Theatre, Belfast.
In 2008, Rachel appeared in BBC reality show I’d Do Anything, where she reached the semi-final stages for the role of Nancy.
The show brought Rachel national fame, and she's been working non-stop ever since. Roles have included the part of Meat in Queen's We Will Rock You - her first West End show - and her current position, playing Elphaba in the hit show Wicked.
This web chat is now closed, but you can read all of Rachel's answers, below.