I have followed multiple leads to her family line, but each seems to lack records but I do believe the following is the most Promising:
Sarah Tailor on her marriage intention was listed as resident of Freetown but you can never find a Tailor/Taylor in Freetown in that time period in the traditional records. Until this morning, when searching through Court records. Two records mention that in 1749 John Taylor and his wife was asked to leave the town, Freetown, MA. Then, again in 1763-64 there is a slightly incomplete record suggesting John Taylor his wife and children... depart. Samuel Braley and Sarah Taylor listed Marriage Intent in March 1764. That is the only Taylor Family listed so far in Freetown at that time.
I can go further to say that there are other court records dating from Middleborough, Plymouth, MA that detail John Taylor and wife, listed as Elizabeth in one record, and his family being asked to leave Middleborough repeatedly. This John is tied to the towns of Halifax, and Scituate. John Tailor of Hanover (10 miles from Halifax) area was married to Elisabeth Gilford/Gifford, he is also most likely the Son of Isaac Taylor born 05 Mar 1659 Concord, Middlesex, Massachusetts Bay who is traced to Scituate, remarried to Sarah (possibly Barron) and died 21 DEC 1766 • Pembroke, Plymouth, Massachusetts, USA. If this information is accurate then John Taylor is the grandson of William Taylor and Mary Merriam.
A John Taylor of Middleborough and his wife Elizabeth are recorded has having three sons born John, Robert, and Daniel between 1719 and 1720. Unknown if the same family, but possible. Could be Elizabeth Felt from Salem, so might not be a match...too many if's, and's or but's to know for sure.
A John Taylor (of Hanover, MA) married Elizabeth Gilford 23 Nov 1730 in Scituate.
Elizabeth Gilford mentioned in the record could be Elizabeth born 1712 and baptized 1725 born to William Gilford and Elizabeth Wright.
There also is another Elizabeth Gilford, William Guilford's sister, their parents are Paul Gilford and Susannah Pullen. Parents died in a small pox epidemic.