Moorehead and her husband, John Griffith Lee, were on the verge of divorce in 1952. They'd long talked about adopting children, but never had any. They separated in 1950. In late 1951, while visiting a children's hospital, Moorehead learned about a woman with 14 children.

Sean was one of them, born in California (with a twin sister) allegedly on January 6, 1949. The boy suffered from anemia, gum disease, severe malnutrition, and some undiagnosed lung problem (bronchitis, pneumonia, or tuberculosis). His mother was putting six of her children up for adoption, and Sean had been in two foster homes already.

Moorehead took pity on Sean, and about December 20, agreed to become Sean's foster mother. (She did not foster Sean's sister. According to Debbie Reynolds, another wealthy Hollywood actor or actress adopted her.)

Moorehead divorced Lee on June 11, 1952. She never adopted Sean (by her own admission), but acted as his foster mother and legal guardian until he was 18.

Moorehead was often on the road in plays or doing films, and Sean lived alone, supervised by maids Freddie Jones and Polly Garland and by a man named Jack Kelk.

Sean spent summers at Moorehead's farm in the Muskingum Valley in southeast Ohio. His letters to her are heartbreaking, begging her to come home and love him, telling her how much he missed her, how he'd been a very good boy and wanted her to see him.

When Moorehead was home, she was a strict disciplinarian. She believed in proper manners, and forced him to act like a Victorian child. She never permitted Sean to be himself around her.

Larry and Mark Russell, the grandsons of a wealthy neighbor, played with Sean sometimes when he was at Moorehead's home in Los Angeles. They said Sean became increasingly possessive of toys, even food.

Sean wanted to be called Eric (although no one knows if "Sean" or "Eric" was his birth name) because he said he hated "being Sean". No one seemed to like him.

Debbie Reynolds and her kids were the exception. She said Sean was nice and well-mannered. Some time between 1965 and 1967, he broke into Moorehead's home safe and stole money from her.

Moorehead sent Sean to boarding schools in Wales and Switzerland. He played piano well, spoke French like a native, and became acquainted with Paulette Goddard (then living in Switzerland).