Frances's birth is often seen as circa 1731 which is not consistent with the birth of George in 1739. Possibly she was some years older - her parents were probably married prior to 1723, but I have no authority for that date either. It's also possible not all these children belong in this family.
It's interesting that the following indicate Vincent Tulloh was a son-in-law as early as March of 1755, and Frances is named as his Tolloh's wife wife in 1757. Yet there is supposedly an Apperson child, William, born in March of 1757.
Louisa Co VA DB B
p.174 21 Feb 1757 Vincent Tulloch, carpenter, and Francis his wife to William Shelton, Taylor. 30#'s. 100 acres. Begin corner Edward Bullocks & John Streets; north fork of Rocky Branch; on Streets line, Edward Bullocks line. Signed: Vincent Tulloch. Wit: Tyree Harris, John (x) Matlock, Thos. Shelton, Francis Austin 24 May 1757 proved by Tyree Harris, John Matlock & Francis Austin.
Frances POINDEXTER and Peter APPERSON were married.2 Peter APPERSON was born (date unknown).
Frances POINDEXTER and Peter APPERSON had the following children:
Frances POINDEXTER and Vincent TULLOCK were married.2 Vincent TULLOCK was born (date unknown).