I found Thankful and Gratia listed as children, not on the census, but inThe Chapin Book of Genealogical Data,Descendants of Deacon Samuel Chapin compiled by Bilbert Warren Chapin,Vol I, first seven generations. Published and copyrighted by Chapin Family Assoicatin Hartford Connecticut.. in the library on film. Page: 131 It has Lieut Joel Chapin (son of Caleb & Catherine [Dickinson] Chapin of Bernardston, MA. b: 22 Apr 1732. Springfield, MAd. 17 Mar 1803/5 Bernardston. 1st MSarah Burke, dau Richard & Sarah [Woodford] Burke. b.1741.Hatfield, MA. d. 16 Apr 1781 children: Chapin 1. Joelb. etc 2. Eddy burkeb. etc 3. Israelb. etc 4. Solomonb. etc 5. Sarah 6. Thankfulb. 11 Nov 1774d. 5 Apr 1812 7. Oliverb. etc 8. Gratiab. ?d. Bernardston, MA also Page: 346 Thankful Chapin (dau. Lieut Joel & Sarah (Burke) Chapin b. 11 Nov. 1774d5 Apr 1812 m. 27 Apr 1799, Joel Warner, son Ichabod Warner, b. 19 Jun, 1773 children: Sarah BurkeB. 8 Feb 1800d m. 14 April 1819Lewis E. Prouty m. again, Warner2nd Gratia Chapin, sister ofhis 1st wife.
I have Lewis E. Prouty in my family line and have his son, Francis Lafayette Prouty's death certificat (copy)which lists Lewis Prouty as father and Sara Warner as mother.
There is also some information about Sara Burk, MA, on Fiche at the DAR Library. also Death Index from NewEnglandAncestors.org. good luck aec in tx