"Massachusetts, Town Clerk, Vital and Town Records, 1626-2001," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:FH5L-73D : 6 November 2017), Margaret Burnham, 26 Sep 1793; citing Death, Ipswich, Essex, Massachusetts, United States, , town clerk offices, Massachusetts; FHL microfilm 777,636.
I found the record for her death. Does this help at all?
26 Sep 1793 in Ipswich, Essex, Massachusetts, United States.