I tried to find parents but was unsuccessful. I did obtain the following sources and added to profile: Sorry I coulnd't be more helpful.
Sources found:
*U.S., Sons of the American Revolution Membership Applications, 1889-1970 Source Info: Military: Name Elizabeth Davis Spouse Francis Postell. Children given: Francis Postell II.
*ELIZABETH DAVIS Info given: ELIZABETH DAVIS married FRANCIS Postell, son of JACQUES Postell and JUDITH. Children of ELIZABETH DAVIS and FRANCIS Postell are: FRANCIS Postell, b. 1760, d.unknown. URL: https://www.genealogy.com/ftm/f/l/e/Teresa-Fletcher-GA/WEBSITE-0001/UHP-0138.html
*Elizabeth Postell (born Davis): Elizabeth Postell (born Davis) was born in 1729, at birth place, South Carolina. Elizabeth married Francis Postell in 1745, at age 16 at marriage place, South Carolina. They had 2 children: Francis Postell and one other child. Elizabeth passed away on month day 1779, at age 50 at death place, South Carolina. URL: https://www.myheritage.com/names/elizabeth_postell
*Register of Carolina Huguenots, Vol. 3, Marion Villepontouxbooks.google.com › books. Horry Frost Prioleau, Edward Lining Manigault - 2010. FOUND INSIDE – PAGE 1431... 1763) 4-Samuel POSTELL (abt 1717-1757) +Mary (Mrs.) POSTELL (abt1717-) 5-Louisa POSTELL (abt 1740-) 4-Jane POSTELL (abt 1723-) +Robert DYMES (abt 1723-) 4-'''Francis POSTELL (1725-1770) +Elizabeth DAVIS (abt 1729-1815)-''' ...