Kelley was raised in
Greensburg, Pennsylvania, the youngest child in a household of six girls and three boys. The two eldest were children of Leonard and Kate Thom; following Thom's 1950 death in a train accident, Kate married mining engineer and inventor Jay Kelley, with whom she had seven children including Sheila. One day during the months immediately following her freshman year, Kelley began suffering from the effects of congenital
hip dysplasia, which ended her hopes of a dance career. Kelley switched to taking acting classes, and graduated from New York University with a
Bachelor of Fine Arts degree. After working in
public relations, she acquired a
talent agent, began performing in plays, and with friends formed an Off-Off-Broadway theater troupe, The Elephant Company. ==Career==