John and Margaret Patterson most likely were recorded in Lancaster Co SC census in 1790. If so, there appears to have been 2 females in the household, one of which may have been a newly born daughter. In 1800 they were in Buncombe Co NC with 3 females age 0-9, and none 10-15. My assumption is that their oldest daughter was born in 1790 and was recorded in both census records mentioned above.
So who was this daughter? What was her name? For several years I have thought she was an Elizabeth who later married James Morrow, as they lived near John and Margaret in Union Co Ga in 1840. However, I have since learned enough about that Morrow family to be convinced that Elizabeth was actually the daughter of Peter Patterson, and therefore John's 1st cousin - not his daughter. Elizabeth and James Morrow's oldest son was named Peter Patterson Morrow - which would carry quite a bit of weight one would think.
Back to the drawing board then... maybe not. Mary Patterson Fountain was a daughter of William Craven Patterson, a granddaughter of Joseph B Patterson (b 1789), and therefore closely related to this whole clan of Pattersons. In 1908 she wrote down the family tree for a nephew of hers. Her notes were not without error, but nevertheless sheds light on the family as a whole in a way many would give their right arm for. Mary named a daughter of John and Margaret as Peggy. She then proceeded to erroneously write that this Peggy married Gravy Foster (Gravet E Foster). Their was a Peggy (dau of Joseph B Patterson) who was b ca 1815 who married Gravet Foster, so she was off a generation.
That said, she still could be right concerning the name Peggy. She may have just named the wrong the Peggy's husband. We do know for a fact that there were 3 daughters born to John and Margaret between 1790 and 1800. Plus, given the fact that sons Robert (1796), John Jr (1798) and George (1800) pretty much took up the latter half of the decade, the 3 daughters most certainly should have dominated the first half of the 1790's. Amy Jane was born in April 1793. A woman named Isabella _____ Price seems to be connected closely to John and Margaret and their family to the degree worthy of considering her a daughter. Isabella was b in April 1792. So a birth year of 1790 for Peggy is quite reasonable, with older brother Joseph having arrived in 1789.
At this time I do not know if this daughter - Peggy(?) - married between 1805 and 1810 or if she died between 1800 and 1810. One or the other happened, however. Perhaps one day we shall learn the true answer to this question.