Easterbrook was born in Los Angeles. She was adopted when she was nine months old; her adoptive parents, Carl and Helen Easterbrook, raised her in Arcadia, Nebraska. She attended and graduated from Kearney High School and Stephens College. Her father was a music professor and her mother was an English teacher at the University of Nebraska at Kearney.
Easterbrook appeared in about a dozen feature films and over 300 television episodes.
One of her earlier successes was in 1980 as Rhonda Lee beginning with season six of Laverne & Shirley. The role of Rhonda was part of the show's change of locale from Milwaukee to Hollywood.
