If you can find a copy of "Alexander Kin" by Charles C. and Virginia W. Alexander, page 34, you can study this family more carefully. Off the top of my head, I don't think it looks like a very good fit.
William and Esther (Brown) Alexander did have a son named Daniel who was b. in 1767 in NC. He was m. in 1794 and did move to Sumner County, TN and also to Maury and smith Counties. I have no death date for him.
According to this book there is conflicting information about WHO he married. One source says Judith Moffatt and another record says Judith Mauphet. The marriage bond in Cabarrus County, NC is the latter. There is no mention of a second marriage - but that's possible, of course.
Daniel b. 1767 also had a son named Daniel - there is no birth date given for him but it does give his death date as 1850 - which would have been the same year that Nancy Elizabeth Alexander was born. There is no wife mentioned for this Daniel.
"Alexander Kin" can be a useful resource, but it is not primary evidence - and so anything found in the book needs to be checked with original records.