Complex sentence: Walker then attended Cambridge University, where she started her acting career with the Cambridge Footlights; her contemporaries included "Spooks" writer David Wolstencroft and comedian Sue Perkins, and was part of the 1990 national tour.
Split into simpler sentences: Walker then attended Cambridge University, 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.