I hope you are still on this forum, you are the first I've seen online, that has the right idea, Elizabeth Fuller & Thos Upson are my ancestors, and she is NOT of the Mayflower line from any Fuller's that I can find records on..
I have Capt Mathew Fuller's Will of 1678 which clearly states his daughter Elizabeth Fuller is married to Moses Rowley, it mentions his wife Francis (was she a 2nd wife?) and his 5 children ,grandkids and son-in-laws that he left money or land to....
Its hard enough trying to find info on Elizabeth Fuller of Hartford, CT without people confusing her with the MA. Mayflower lines, according to all my Upson & Welton Records Elizabeth (Fuller) Upson was re-married to Edmund Scott by 1671,in a 1681 census Hartford,CT.she is still his wife,Eliz is not listed in Scott's 1690 Will, she was appartly dec'd