I can't say I have any solid information on the ancestry of Catherine DeGroat Weyant.It does seem likely that Catherine and Mary were sisters, as well as, sisters-in-law, probably daughters of William DeGroat/DeGrote/DeGroot. A William DeGrote married Sarah Underhill in the New Windsor Presbyterian Church on 8 September 1796.
There seems to be some question on many of the Weyant wives through the generations.John Weiant (1765-1843) is sometimes shown to have married a daughter of Capt. Arthur Smith and his wife, Elizabeth Purdy, but I have seen nothing to support this.
Hannah Rider (or Reeder) was the mother of John Weiant(1765-1843) and his second wife was Mary Rider.Was there a relationship between these two ladies?Some have suggested that Hannah was a daughter of John Rider and Mary Paine, but their daughter, Hannah appears to have been born in 1758, far too young to have married in 1764.
It has been suggested that Mary Rider Weyant was Mary Ann Rider, daughter of King Rider and Rosannah Hunter, but it appears that Mary Ann Rider married Anthony Cock.
I would appreciate learning more about the various Weyant wives and their ancestries.