Sharon was born in South Euclid, Ohio a suburb of Cleveland, and grew up there with her noisy and rowdy family: her parents (Ann and Arvel), her sister (Sandy), and her three brothers (Dennis, Doug and Tom). In the summer, they usually took a trip, they all piled in a car and headed out to Wisconsin or Michigan or once to Idaho. Her trip to Idaho was the inspiration for her book Walk Two Moons.
It was in college, where she took literature and writing courses, that she became intrigued with story telling. Sharon received her BA at Ohio's Miram College and her Master of Arts from the University of Virginia. Her previous jobs include teacher, editorial assistant, indexer and a researcher. Sharon started writing novels for adults and published two books while she lived in England having moved there in 1979. She then wrote Absolutely Normal Chaos and since then has mainly written about young people.