Yes, this is the Rachel Drewry who married Thomas Hearne. I have a copy of the listings of couples getting a marriage license in Montgomery County NC in 1788.(Thanks to another researcher, thanks Barbara!)
I do have information on the Hearnes. The early part is mostly from the Hearne book, but the later generations, i.e. of Mary Hearne (daughter of Rachel Drewry and ThomasHearne)and her husband Thomas H. Harris, are documented by family papers.
Email me at firstname.lastname@example.org to continue exchanging info, if you want. Don't give up the genealogy. It is a great hobby, full of surprises and detective work. Hoping to hear from you. Carol Shough