The daughter of two school teachers, Grayden was born and raised in Manchester-by-the-Sea, Massachusetts, and began performing at age five. After graduating cum laude from Barnard College where she majored in American Studies, she worked as a performing member of the 'Drama Department' in New York City. Her additional theater credits include Hopscotch, The Vagina Monologues, Fool for Love, Hamlet, Waiting for Lefty and Ordinary Day. Her television credits include a recurring role on HBO's Six Feet Under (2001), a starring role on Fox Television's John Doe (2002), and a guest appearance on Law & Order: Special Victims Unit (1999). Her feature film credits include Dad (1989) starring Jack Lemmon.