Walger began her career on British television. In 1998, she guest starred in an episode of ITV crime series, Midsomer Murders. She had the recurring role in the BBC 1 sitcom Goodnight Sweetheart in 1999, and appeared in two episodes of the crime/drama The Vice. Also in 1999, she played the daughter of newspaper magnate Max Van der Vuurst, Hilde, in the Heat of the Sun story "The Sport of Kings". The following year, Walger made her film debut in the biographical drama Eisenstein. In 2001, she moved to United States and was cast as Donna Barnes on the HBO comedy series, The Mind of the Married Man . The series was canceled after two seasons. In 2003, she starred on the short lived U.S. version of Coupling, which aired on NBC. In 2004, Walger played Nicole Noone opposite Noah Wyle in the TNT television film, The Librarian: Quest for the Spear, for which she received Saturn Award for Best Supporting Actress on Television nomination.