I have been trying to figure that one out too. If it is as it appears then the same Ann Mathewson was Robinson's mother-in-law and also his daughter's mother-in-law. There were several Anns (Mathewson/Matheson/Mathison) appearing in the census records of 1851/1861/1871 - in several different counties that could be connected: Vaughn Twp, Osprey, etc. I think the key here is isolating which William Mathewson we are dealing with: where was he before he married Elizabeth and who was his father? I am going to try to find out who the Andrew Mathewson was that appears on the 1837 rebellion list of prisoners found by Marcia.