Following is what I believe is satisfactory, though indirect, evidence that would allow you to connect Joseph and Thankful as husband and wife. Joseph Plumb died in Farmington between 22 September 1741 (date of will) and 9 June 1742 (date will proven in Hartford Probate Court.) His will names "Thankful Plumb, his wife, as executor of his estate.) In October 1743 Joseph Gaylord was appointed to sell certain of Joseph's real property. His minor children chose as their guardians (children's names followed by guardian): Lois - Samuel Gaylord; Amariah - Uncle Joseph Gaylord; Sibbel, Simeon, and Galaliel - Deacon David Gaylord. The surname of Uncle Joseph being Gaylord would indicates that the children's mother's last name at birth would have been Gaylord. The probate does not identify the date of marriage. Lois, the oldest child, was 13 on 8 November 1741 per papers filed in the probate, so marriage would have been no later than early February 1728. Source is: Manwaring, Charles William; A Digest of the Early Connecticut Probate Records, (Hartford, Conn.; R. S. Peck & Co.; 1904). Available through Internet Archive: (https://archive.org/details/digestofearlycon03manw) Hartford District, 1729-1750, Volume 3, pages 442 - 444.