In private, Jacques led a turbulent life. She was married to the actor John Le Mesurier from 1949 until their divorce in 1965, a separation caused by her five-year affair with another man. Jacques, who had been overweight since her teenage years, suffered ill-health soon after the separation from Le Mesurier and her weight rose to nearly <ins></ins>. She died of a heart attack on 6 October 1980, at the age of 58. Her biographer, Frances Gray, considers Jacques had a "talent for larger-than-life comedy which never lost its grip on humanity", while she could also display "a broader comic mode" as a result of her "extraordinary versatility".