Susan's first marriage to actor Jess Barker was a stormy one that ended with a bitter custody battle of her twin sons and a suicide attempt by Susan. Her second to rancher Eaton Chalkley was a long and happy marriage until he died suddenly of hepatitis nine years later. Susan left Hollywood for five years in a state of deep mourning. She would later return in 1971.
Susan was diagnosed with brain cancer, allegedly the result of being exposed to dangerous radioactive toxins on location in Utah while making The Conqueror. All the lead actors John Wayne, Agnes Moorehead, John Hoyt, Hayward, and the director Dick Powell died of cancer. The case is still a scandal.