Kavanagh was educated in Brussels, and trained as a drama Teacher at Bretton Hall College and as an actor at Bristol Old Vic Theatre School. Her first known appearance was as Nicky in a 1984 episode of Minder. In 1990 she played the lead in the first production (in Scarborough) of Alan Ayckbourne's The Revengers' Comedies, opposite Jon Strickland.
In 1994 she appeared as Penny Winter in eight episodes of Seaforth. The following year she played Rosina Lagrange in three episodes of The Glass Virgin. In 2009 she starred as Christine O'Connell in Doctors (after originally appearing as June Mobley three years earlier). She played Lucy Downes in the Inspector Morse ITV series, in the episode "The Wolvercote Tongue". She has also been a member of the BBC Radio Drama Company for BBC Radio 4.
