Born in Norfolk, Virginia to wealthy stockbroker Cornelius Hancock and heiress Garland Council Sullavan, Margaret Brooke overcame a muscle weakness in her childhood to go on to become a rebellious teenager at posh private schools. She went on to perform with the University Players at Harvard and made her Broadway debut in A Modern Virgin in 1931. Her Christmas Day marriage in 1931 to Henry Fonda lasted only a few months, and her later marriages to director William Wyler and agent Leland Hayward were also tempestuous. Two of her three children, Bridget and Bill, would spend some time in mental institutions, and friends noted that the collapse of her family life led to her breakdown. Her condition worsened over time, until she was discovered unconscious from barbiturate poisoning in a hotel room. Her death was ruled accidental by the county coroner.



Divorced Henry Fonda after two months. Mother of actress Brooke Hayward. As a child, family friend Peter Fonda had a crush on Sullavan's daughter Bridget. In adulthood, after Bridget committed suicide, he named his own daughter (Bridget Fonda) after her. She suffered from a congenital hearing defect called otosclerosis that worsened as she aged, making her more and more hard of hearing. Her voice developed its distinctive throatiness because she could hear low tones better than high ones. Her son Bill committed suicide in 2008. He was 66 years old. On January 4, 1960, after having received the toxicologist's report on the contents of the vital organs, the coroner ruled Sullavan's death accidental. Her death was caused by barbiturate poisoning, "but not such a massive overdose as one would expect in a suicide attempt".