In 1950, Thurston and actor Ross Elliott became engaged, even going so far as to set the date, November 23. That date came and went, however, without incident; less than three weeks later, the wedding was called off. In July 1956, Thurston embarked on her second marriage; this time, to television actor John Russo (1925–2003, known variously as John Duke, Barry Russo, J.D. Russo, and John Duke Russo). By 1959, the two had become estranged, and by February of that year, Thurston was dating actor Jay Douglas (1907-1996). By January 1960, notwithstanding the fact that neither party had as of yet even initiated divorce proceedings, each spouse was clearly otherwise engaged – Russo (aka Duke), with Actress Dolores Michaels; Thurston, with Screenwriter Robert Creighton Williams. Eventually, the divorce was finalized, and, on February 7, 1962, Thurston and Williams were wed. So they would remain until Thurston's death at the age of forty-nine, on New Year's Eve 1969. In the years since her death, the prevailing rumor was that Ms. Thurston committed suicide. However, her daughter, Amanda Thayer, has disputed this, insisting that she witnessed her mother in a Los Angeles hospital after she succumbed to heart failure and spent her last hours in a coma. She was survived by her husband, who died in 1976 at the age of fifty-two, her daughter, and a grandson.