Kates has appeared in numerous films and television series, including one of the first Seinfeld episodes. Her first film was Bill & Ted's Excellent Adventure, in which she played Princess Elizabeth, her best known role, also starring Keanu Reeves and George Carlin. Kates studied acting at the Beverly Hills Playhouse for ten years with Milton Katselas. She is currently involved in producing numerous new films, including Standing Down with Ron Perlman and Pras. In April 2009, she completed working on a documentary with william Shatner and Ben Folds, entitled William Shatner's Gonzo Ballet with her partners at Big Screen Entertainment and Five Star Pictures, Michael Manasseri, Scott Woolley and David Zappone.