She was killed by her ex-lover Stan Carter, aka Sin-Eater, in the story arc suitably named "The Death of Jean DeWolff." After she was killed, Spider-Man discovered that she kept a collection of photographs of him and of the two of them together. (One of them originally featuring the Black Cat, had been altered to remove the Cat from the image.) This implied that her feelings towards him were warmer than she generally indicated, leaving Spider-Man somewhat dejected after he searched her apartment.
Jean DeWolff appears in The Spectacular Spider-Man, voiced by Irene Bedard. She is shown to be partnered with Stan Carter.