Clark was born Nora Golding in Sarnia, Ontario, the daughter of Eleanor Almond (née McNaughton) and George Raymond Golding. Clark grew up in Toronto, Ontario, where she attendedNorthern Secondary School. She was one of several successful entertainers and many notable persons to have attended this school. She married Alex Karras, who became her Webster co-star, in 1980 and their daughter Katie was born the same year. They met when they costarred in the TV movie, Babe, in which she played Babe Didrikson Zaharias (for which Clark would win an Emmy in 1976), and he played her husband, professional wrestler George Zaharias. Clark and Karras remained married until his death on October 10, 2012.