Offner was born in New York City in 1959. Her father was Mortimer Offner, a photographer, screenwriter, and TV and theatre director. He wrote many of Katharine Hepburn's early films, but he was blacklisted. Her mother, Pauline, was a photography editor and worked for the first medical photography journal Scope. She went to Sarah Lawrence College and NYU School of the Arts, and after graduating she continued to work in theatre on and off Broadway. She has since appeared in Act One at the Lincoln Center, and in film