I don't trust abstracts very much because of the many occasions I've encountered where abstracts occasionally reflected additional suppositions not supported by the actual text of the wills. I have transcribed copies of the original wills, with sources, on my website or I don't have them at all.
I do not believe that Sarah Abernathy was from Scotland. I suspect that she was born in the Virginia Colony, one of the Robert Branches there. We have several where there are likely daughters whom we cannot identify because there is no extant documentation. Especially pre-Revolution.
And speculation on Robert (1st) Abernathy's parents requires, in my opinion, far more work for which I believe I have little time left on this earth to accomplish.
Charlie, Robert 4th did not, repeat, NOT list a son James in his will. Period. James was a witness, yes, but not cited IN the will. I seriously doubt that James was a close relative but was, in fact, probably a cousin at most, and clearly related or the Y-DNA matches wouldn't be such strong evidence!
Beware of a propensity to assume what is NOT supported by actual documentation.