An Abigail Remington, daughter of Matthew deceased, married Anthony Olin, son of Henry Jr., in 1793. Is Anthony's father the second husband of Abigail's mother, Martha (Randall) Remington? Or did Martha marry Henry Sr.? (needs more research)
The dates of Martha's two marriages do not seem to jive. Was she a lot younger than Matthew? If she remarried to Henry Olin, which one, Sr. or Jr.? If her daughter Abigail, by Matthew, married Anthony Olin son of Henry Jr., it seems that Abigail could not have been born much before 1770 or so. Is there a generation missing here, possibly a Matthew Remington Jr.? Or, perhaps Matthew had an earlier wife who died, and he remarried to a younger woman, who was Martha?
I have put together all the data -- including marriage records and Henry's will -- into what I believe is the most likely scenario, given the information I have. If Martha Randall Remington married this Henry, and is indeed the Martha mentioned in his will, she could not have been the mother of his children, because some of them were already married with children at the time of his will; therefore she was probably his second wife. The codicil to his will makes it clear that there was another wife named Sarah; this also agrees with the marriage records.