Mary Whitney was born 21 April 1694 in Watertown, Middlesex County, Massachusetts to Joseph Whitney (1651-1702) and Martha Beach (1650-1711) and died 27 February 1739 Waltham, Middlesex County, Massachusetts of unspecified causes. She married John Knapp (1688-1730) 13 July 1715 in Newton, Middlesex County, Massachusetts.
Children
| Name | Birth | Death | Joined with |
| Sarah Knapp (1716-1736) | |||
| David Knapp (1717-1773) | 12 March 1717 Newton, Middlesex County, Massachusetts | 1773 Spencer, Worcester County, Massachusetts | Sarah Bartlett (1712-1767) |
| Martha Knapp (1719-1721) | |||
| Bathesheba Knapp (1721-1745) | |||
| Isaac Knapp (1724-) | |||
| Josiah Knapp (1723-) | |||
| James Knapp (1726-) | |||
| Mary Knapp (1726-1810) | |||
| Lydia Knapp (1730-1802) | |||
| Amelia Knapp (1731-) | |||
Siblings
| Name | Birth | Death | Joined with |
| Joseph Whitney (1675-1737) | 15 August 1675 Watertown, Middlesex County, Massachusetts | 15 July 1737 | Hepzibah Flagg (1678-1737) |
| Martha Whitney (1677-1702) | |||
| John Whitney (1680-1760) | |||
| Isaac Whitney (1681-1681) | |||
| Isaac Whitney (1682-1702) | |||
| Benjamin Whitney (1684-1736) | |||
| Mary Whitney (1694-1739) | 21 April 1694 Watertown, Middlesex County, Massachusetts | 27 February 1739 Waltham, Middlesex County, Massachusetts | John Knapp (1688-1730) |
| Sarah Whitney (1698-1752) | |||