When Mary Alvord Weller was born on 11 September 1672, in Northampton, Hampshire, Massachusetts Bay Colony, British Colonial America, her father, John Weller, was 27 and her mother, Mary Alvord, was 21. She married Jonathan Bagg on 7 January 1697, in Springfield, Massachusetts Bay Colony, British Colonial America. They were the parents of at least 3 sons and 6 daughters. She lived in Northampton, Hampshire, Massachusetts, United States in 1672. She died in June 1740, at the age of 67.