There may be something "off" with this woman. She was thought to be the first wife of Lieutenant Samuel Street, of Wallingford, based on Savage. It looks like she was the wife of a different Samuel Street. They married in 1684 and had children 1685, 1686, and 1688.
I haven't researched the marriage to James Fountain or his details, but he was born in 1681, and they had children around 1700. If that is correct, she would have been in her mid to late 30s at least, perhaps older, and several decades older than her second husband.