Forbes is known for her recurring appearances on genre and drama shows such as Ensign Ro Laren in ' and her regular role as medical examiner Julianna Cox on ' during the 1990s, while building her career with recurring roles throughout the 2000s in "Battlestar Galactica", "24", "In Treatment", "Durham County", "Prison Break" and her series regular role as Maryann Forrester on "True Blood". She has appeared in significant roles in movies such as "Escape from L.A.", "Kalifornia", "Swimming with Sharks" and "Columbus".