In my working database, I have 9 sons and 5 daughters for Nathan and Eve Cline Abernathy, but at least one possibly two of those daughters is "not proven", in my opinion.
I have used the excellent Old Macedonia Website you created very extensively to provide support to what is available from census records, but only two of those children can be "proven" from 1850 and later census records (Letty being one of the questionable daughters), and three of them cannot even be substantiated by inference from the 1820, 1830, and 1840 census records.
I am not of this lineage, and have not communicated at length or in great detail with any who are, although one has sent me a descendancy chart, which I am retaining pending further investigation.
My Abernathy ancestor was David Abernathy Sr of Lincoln County NC (of gr-grandson of Robert 1st Abernathy of VA). Based on some evidence I have, the lineage of Nathan may not be related to the lineage of the first Robert Abernathy at all. I have been trying to locate direct line males of this lineage to obtain DNA samples to determine if the lineage is or is not related to the first Robert Abernathy. So far the answer is not encouraging: one Y-DNA data result (however damning it appears) simply can NOT define a lineage! And the Y-DNA data results form an individual traced to one of Nathan and Eve's sons is clearly not even close to matching the accumulated profile of the Robert Abernathy Lineage, so more data is needed.
Are you aware, sir, that on the 1820 NC census there are not one, but two Nathan Abernathy families? One is located in Lincoln County and the other in Burke County. There is one daughter and no sons listed for one of the Nathan Abernathy families and 2 daughters and 5 sons listed for the other Nathan Abernathy family. Both Nathan Abernathy families are also on the 1830 census. The one in Burke County has one daughter and no sons, the one in Lincoln County has tally marks for 7 sons and three daughters.
In 1840 one of the Nathan Abernathy families in Lincoln County has tally marks for 8 males of various ages and one young female, the other has only the one young daughter. The Nathan Abernathy family in Burke County has the daughter who first appears on the 1820 census and her very elderly parents. The 1840 census records for William Summey and John Goodson are more or less consistant with what I have for those two families, but they aren't exactly my present concern.
I cannot explain what precise relationship is the Letty Abernathy who is found on the 1860 census in the household of a probable grandson of Nathan and Eve. I list her as a daughter, but I am far from positive about it, because if she was an unmarried daughter I would have expected to have found her on the 1850 Cass County census with parents Nathan and Eve and she is simply not there. If, according to your information, I am missing an unnamed son of Nathan and Eve (Cline) Abernathy, then she could be his widow. In fact, the evidence suggests that she may have been widow of the young Nathan from the 1840 NC census, but I don't know if that will ever be proven.
Sometimes one has to accept that more questions than answers is all one may ever get.