I'm brand new to the McGuffin realm. I stumbled onto the name Elizabeth McGuffin when I was trying to find out something or anything about a HVR1+HVR2 mtDNA match I have with a lineage in Oregon. That line gives the earliest known female as born in 1859 in Oregon. But I saw (if I remember right) two earlier generations on ancestry.com that ended up with an Elizabeth McGuffin (I think it was) from Bath County, Virginia, but with no other information.
As for my own earliest known female ancestor, she was Charity with unknown last name, born in 1760, Anson-Richmond County, NC. It looks to me that Charity's parents moved down there from Virginia, and may have been somehow related to said Elizabeth McGuffin on the maternal side.