I too am a gggranddaughter and have not yet found out just who this "grandma Nancy" was. I must confess I have not looked as dilligently as I perhaps should have. You are the first to offer reasonable surnames that could lead to accurate discovery.
Please feel free to contact me at PWEYEL@SBCGLOBAL.NET, if you wish to do so.
Another descentant in Mississippi and I are trying, between other obligations and activities, to go over original documents to verify our Texas to Mississippi James connections back through Tenneessee to North Carolina to Liverpool and beyond. We have been finding an error or two in the indexes and translations of old documents provided as the usual "proofs."
Best of good wishes on your hunt.
PWeyel
San Antonio