Thankful Thayer Holbrook was born 4 August 1725 in Mendon, Worcester County, Massachusetts to Samuel Thayer (1696-1764) and Mary Sampson (1694-) and died 10 December 1798 Massachusetts of unspecified causes. She married Sylvanus Holbrook (1715-1782) 14 April 1748 in Mendon, Worcester County, Massachusetts.
Children
| Name | Birth | Death | Joined with |
| Sylvanus Holbrook (1750-1828) | |||
| Ruth Holbrook (1752-1781) | |||
| Rachel Holbrook (1753-1832) | |||
| Margaret Holbrook (1755-1805) | |||
| Comfort Holbrook (1756-) | |||
| Thankful Holbrook (1760-1834) | |||
| Mary Holbrook (1762-1814) | 1 February 1762 Uxbridge, Worcester County, Massachusetts, United States | 27 December 1814 Mendon, Worcester County, Massachusetts, United States | John Benson (1749-1818) |
| Stephen Holbrook (1764-1830) | |||
| Abigail Holbrook (1765-) | |||
| Henry Holbrook (1768-1868) | |||
| Lucy Holbrook (1770-1843) | |||
Siblings
| Name | Birth | Death | Joined with |
| Abigail Thayer (1718-1774) | |||
| Samuel Thayer (1721-) | |||
| Zilpah Thayer (1722-) | 13 September 1722 | 17 October 1761 | John Holbrook (1717-1773) |
| Mary Thayer (1723-) | |||
| Thankful Thayer (1725-1798) | 4 August 1725 Mendon, Worcester County, Massachusetts | 10 December 1798 Massachusetts | Sylvanus Holbrook (1715-1782) |
| Comfort Thayer (1728-1761) | |||
| Margaret Thayer (1730-) | |||
| Susanna Thayer (1731-) | |||
| Stephen Thayer (1733-1781) | |||