As a child Shaver suffered from a heart disease that led to a long convalescence, during which she became interested in acting. She studied theater at Alberta's Banff School of Fine Arts. She briefly moved to Los Angeles but lacked the proper working papers and so got no acting jobs. Shaver returned to Canada and spent five years gaining experience on stage and screen, debuting onscreen in the Canadian film Shoot (1976). In 1978 she returned to Hollywood and since then has worked steadily in both America and Canada.