Christina Ann "Kristy" McNichol (born September 11, 1962 in Los Angeles, California) is a former two-time Emmy Awar winning Golden Globe nominated actress best known for her roles as Letitia "Buddy" Lawrence on the TV drama Family, and as Barbara Weston on the sitcom Empty Nest. She is also the sister of former child actor Jimmy McNichol. McNichol's career came to a sudden close when she was diagnosed with bipolar disorder in 1992.