Sarah Hagar Whitney was born 1 September 1651 in Watertown, Middlesex County, Massachusetts to William Hagar (1620-1684) and Mary Bemis (1624-1695) and died 7 March 1746 Weston, Middlesex County, Massachusetts of unspecified causes. She married Nathaniel Whitney (1646-1732) 12 March 1673 in Watertown, Middlesex County, Massachusetts.
Children
| Name | Birth | Death | Joined with |
| Nathaniel Whitney (1675-1730) | 25 March 1675 Watertown, Massachusetts, United States | 23 September 1730 Watertown, Massachusetts, United States | Mercy Robinson (1676-1740) |
| Sarah Whitney (1678) | |||
| William Whitney (1683-1721) | 6 May 1683 Watertown, Middlesex County, Massachusetts, United States | 24 January 1721 Weston, Middlesex County, Massachusetts, United States | Martha Peirce (1681) |
| Samuel Whitney (1687-1753) | |||
| Hannah Whitney (1688-1768) | |||
| Elizabeth Whitney (1692) | |||
| Grace Whitney (1700-1719) | |||
| Mercy Whitney (1702) | |||
Siblings
| Name | Birth | Death | Joined with |
| Mary Hagar (1645-1646) | |||
| Samuel Hagar (1647-1703) | 20 November 1647 Watertown, Middlesex County, Massachusetts | 16 February 1703 Watertown, Middlesex County, Massachusetts | Sarah Mixer (1657-1745) |
| Hannah Hagar (1649-1702) | 21 November 1649 Watertown, Middlesex County, Massachusetts | 6 May 1702 Watertown, Middlesex County, Massachusetts | Joseph Priest (1649-1697) |
| Ruhamah Hagar (1647-1702) | |||
| Sarah Hagar (1651-1746) | 1 September 1651 Watertown, Middlesex County, Massachusetts | 7 March 1746 Weston, Middlesex County, Massachusetts | Nathaniel Whitney (1646-1732) |
| Susanna Hagar (1653-1722) | |||
| Diana Hagar (1655-) | |||
| Elizabeh Hagar (1658-) | |||
| William Hagar (1659-) | 20 November 1647 Waltham, Middlesex County, Massachusetts | Sarah Benjamin (1663-1745) | |
| Rebeckah Hagar (1661-1735) | |||
| Abigail Hagar ((1664-1736) | |||
| Mehitable Hagar (1665-1691) | |||