Walker then attended New Hall, Cambridge, where she started her acting career with the Cambridge Footlights. Her contemporaries included Spooks Writer David Wolstencroft and Comedian Sue Perkins, who were all part of the 1990 national tour. Perkins, then an older undergraduate, was assigned to be her "college mother", although Walker later said: "She was the worst college mother I could have had .. They’re meant to hold your hand. She asked to borrow my bike, got drunk and I never saw it again." Walker acted on stage as Perkins's stooge and years later their partnership was resumed when Perkins cast Walker in her sitcom Heading Out.