Cabot was born Harriet Pearl Shapiro on July 9, 1927, to a Jewish family in Boston, Massachusetts. She led an early life filled with turmoil; after her father abandoned their family, Cabot’s mother Elizabeth was institutionalized, leaving Cabot orphaned. She was subsequently raised in eight different foster homes, and stated that she spent much of her childhood in the Bronx. It was posthumously revealed that, while in foster care, Cabot suffered emotional and sexual abuse, which triggered intense post-traumatic stress disorder.

Cabot attended high school in Manhattan, and found employment as an illustrator of children’s books. She supplemented her income by working as a singer, performing at the Village Barn club in Manhattan. She married her first husband, the artist Martin Sacker, on July 30, 1944, in Washington, DC, while still a minor. Sacker was a childhood friend, and the marriage presented Cabot an opportunity to leave foster care.

Based on her performances in the On the Isle of Samoa and Tomahawk, Cabot appeared as a lead in a series of roles in similar Western and Arabian-themed films, such as The Battle at Apache Pass and The Duel at Silver Creek, and Son of Ali Baba (all 1952). In 1953, she starred in a further two Westerns: Gunsmoke and Ride Clear of Diablo.

Dissatisfied with her film offers, Cabot asked to be released from her contract in 1954. She returned to New York, and resumed her stage career with a role in a Leonard Kantor-directed, Washington DC-based production of Harold Robbins’ A Stone for Danny Fisher. Cabot studied acting with Sanford Meisner in New York, and continued to pursue a stage career, appearing in a short-lived run of the musical Shangri-La in Boston in 1959.

Cabot bore her only child, a son, in 1964. In 1968, she married her second husband Michael Roman with whom she raised her son, Timothy Scott Roman, before again divorcing in 1983.

In the last years of her life, Cabot suffered from depression and suicidal thoughts, and was prey to a wide range of irrational, powerful fears. She was under a licensed psychologist’s care, but the psychologist found her so troubled and ill that the sessions became “emotionally draining.” Cabot became increasingly unable to care for herself; the interior of her home was littered with years of trash, and spoiled food lay everywhere. In late 1986, Cabot’s mental health deteriorated significantly. Despite the squalor of the home’s interior, Cabot still maintained a “adequate” income despite having retired from acting, largely due to real estate investments and her fascination with vintage cars, which she regularly acquired, restored, and resold.

On December 10, 1986, Cabot’s 22-year-old son, Timothy Scott Roman, beat her to death in her home in the Encino neighborhood of Los Angeles, with a weightlifting bar. He was charged with second-degree murder.

At the close of the trial, prosecutors changed the charge to involuntary manslaughter, as no evidence had been presented at trial to support premeditation (which was required for a murder conviction). Superior Court Judge Darlene E. Schempp deliberated 10 minutes, and then convicted Roman of involuntary manslaughter. Roman, who had already spent 2 ⁄2 years in jail, was sentenced to three years’ probation on November 28, 1989.