Sarah Margaret Roffey was born in
London,
England, the daughter of Anne (née Murphy) and Peter Roffey. Her mother was a
nurse practitioner whose specialty was women's health. The Roffey family, including Sally and her three siblings, enjoyed the outdoors, and Sally went sailing and hiking from a young age. She attended
Seattle Country Day School during her elementary years, and in 1973 graduated from
Renton High School. Roffey attended the
University of Washington, first planning to become a dental hygienist. She switched to pre-dental at the encouragement of a roommate.