She won a Tony Award in 1980 for her performance in the Broadway production I Ought to Be in Pictures. She also played Libby Tucker in the film version in 1982. She appeared in the hit film Ordinary People in 1980. From 1988 to 1995 she starred as Carol Weston in the sitcom Empty Nest. Her last role came in the movie Bart Got a Room in 2008. Dinah married Arthur Mortell in 1997 and was previously married to Jean-Marc Joubert. She has three children.