Samuel Garrison b. abt. 1740 probably Rockland County

Enlisted in Col DuBois 5th Regiment in Haverstraw, Orange County (now Rockland County). Had two verifiable children: John b. abt 1756 and Samuel b. abt 1777 as they were awarded Bounty Land in upstate Sterling Township, NY for their fathers’ service..

I am trying to find out the mother of Samuel M. Garrison b. abt. 1777 in Rockland County, lived a large portion in Monroe, NY. His Mother may have lived with him as his father died in the Battle of Fort Montgomery when he was a baby and I have no information on her.
Samuel married Abigail Porter, also of Rockland County, b. abt. 1782 - 1868. They had:
1. Theziah Garrison 1796-
2. Mary Ann Garrison (1808-1889) who married Jacob Bailey of Baileytown
3. Walter Garrison (1808-1887) married Adelina Lamoreaux (1803-1880)
4. Hiram Garrison (1814-1897) died in Michigan
5. William H. Garrison (1817- ) married 1st Hester Jane Scofield, 2nd Clorinda Fleming, wid of Lord (William and Hester are my direct line)
6. James Garrison
7. Nancy Garrison

I have found two theories, I've been unable to prove either. First is that of Mary Morgan of Salem NJ and the other is Ealtie Ryder.

I appreciate any assistance you may be able to offer.