Mary Barrett Thayer was born circa 1632 in Norwich, Norfolk, England to Thomas Barrett (1593-1668) and Margaret Huntington (1608-1681) and died 2 April 1657 Braintree, Norfolk County, Massachusetts of unspecified causes. She married Shadrach Thayer (1629-1678) 1 March 1654 in Braintree, Norfolk County, Massachusetts.
Children
| Name | Birth | Death | Joined with |
| Rachel Thayer (1655-1656) | |||
| Thyall Thayer (1657-1736) | |||
Siblings