Barnes was born December 7, 1958 in Fort Dix, New Jersey, the third of four children of a father who was a major in the United States Air Force. Her mother was a housewife. Barnes's childhood was marked by a series of moves across various military bases in the United States before her family settled in Lancaster, California. After graduating from Antelope Valley High School at age 17, she relocated to San Diego, working as a waitress and a dancer.