A little late in responding, but, yes, if Louisa was born 1791 she would have to be the daughter of John Coltharp Sr. but not by his Hamner wife. He married second Mary Crowder in Mecklenburg VA 10 Feb 1784 and probably had several children by her including Eli Strange born 4 Feb 1784 (yeah, those dates are confusing as well!) and Nancy Catherine born VA ca. 1788 who married Andrew Pangle. Louisa would fit here, but as I've said, I've never seen a shred of proof she was a Coltharp. I've also never seen proof that Richard White's first wife, supposedly Elizabeth, was a Coltharp, but I'm willing to buy that one since Sarah Coltharp b. VA ca. 1780 and probably a daughter of John and "Mary" Hamner was in Richard White's son's household in IL 1850 and 1860.