Mariclare Costello

Mariclare Costello (born February 3, 1936) is an American actress and educator. She is a lifetime member of The Actors Studio. Her best known roles were as Rosemary Hunter Fordwick on the television series "The Waltons," from 1972 to 1977. 
In 1977, after her role on "The Waltons", she played Maggie Fitzpatrick on the short-lived drama show "The Fitzpatricks."
Costello was born in Peoria, Illinois. From 1977 until his death in 2013, she was married to actor Allan Arbus. She is an acting professor at Loyola Marymount University in Los Angeles.