Marshall was married five times. She had three children with her first two husbands. Marshall's third marriage was to director Hal Ashby in August 1969; she divorced him a year later in 1970, and married for a fourth time to Jeffrey A. Stein in 1978, whom she also divorced. In 1990 she married for a fifth time, this time to executive Mel Bartfield. The couple relocated to Montego Bay, Jamaica, where they remained until her death, at age 61, on June 28, 1992.