She was cast as the role of British surgeon Elizabeth Corday starting from the fourth season on September, 1997.
Her movie credits contain Crashing in 2007, Sweet Land in 2005, Boudica in 2003 in which she played the eponymous Boudicca, Essex Boys in 2000, Croupier in 1998, The Infiltrator in 1995, A Pin for the Butterfly in 1994, and The Cook, the Thief, His Wife & Her Lover in 1989.
Kingston receives North American TV renown after being cast on the long-running medical play ER.
In October that same year, she performed in the police technical play CSI: Crime Scene Investigation in season 9: episode 3 named "Art Imitates Life" where she represented Patricia AL wick, a therapist and sorrow counselor who helps the group manage with the fresh death of CSI participant Warrick Brown.
Kingston acted Lady Macbeth reverse Kenneth Branagh in Macbeth at Manchester Worldwide Festival.
Despite her arrogant and opinionated exterior, she has a deeply caring side to her - she is there to provide support at critical moments for both staff and patients alike.