"I stand up!"
Quentin's early acting work included appearing on stage in the chorus of the original cast of the musical Les Misérables.
In July 1996, Quentin released a single, a cover of the Exciters' hit "Tell Him", with her Men Behaving Badly co-star Leslie Ash under the name of "Quentin and Ash". The single reached number 25 in the UK Charts and disappeared three weeks later. From 1997 until 2000 Quentin starred alongside Alan Davies in Jonathan Creek playing the character Maddie Magellan, an investigative journalist, who uses Jonathan's mind to solve murder mysteries.
Quentin has also appeared in the 2001 telefilm Hot Money, which was based on the true story of the theft of hundreds of thousands of pounds from the Bank of England. In 1998 came the first sitcom to be built around Quentin herself, Kiss Me Kate. At the British Comedy Awards in 2004, Quentin won the "Best Comedy Actress" award for her performance in Von Trapped and in the same year, she started the major role of Maggie Mee in the popular drama Life Begins, which returned for a third series in 2006.
ITV has produced five series of the police drama, Blue Murder, in which Quentin plays the main character, DCI Janine Lewis where she plays against type. The pilot aired in the UK on 18 May 2003.