I am another descendent of Humphrey's This is the information I have on his family ( I have more on both the Acheson and Reed parents)
Humphrey (Little Britain Township, Lancaster Co, PA: 1740-d. 1814, Hickory, PA) and Rebecca Reed (b. 1739/1742/44 Martic Township--before 1785/ 1790 Hickory, Washington Co, PA) married Dec 3, 1764/~1765 in Lancaster Co. 10-12 children. Moved to Washington Co ~1778/9 (by which time Rebecca had died-Humphrey took a second wife,Elizabeth Hull (?)
The story goes that Humphreywas apprenticed to the Achesons' neighbor, David Reed, to learn farming. He not only got along well with David, but also fell in love and. married David's daughter Rebecca. There were three marriages between Reeds and Atchisons: Humphrey's older brother Matthew married Rebecca's older sister Jean/Jane (1738-4/25/1801) in 1760 and his younger sister Ann married Rebecca's younger brother, John(1744-1817). Humphrey lived on his own farm in Little Britain Township from 1767-1779. His children included David, John (1774), Humphrey Jr, Mary /Polly, Catherine, Ann(1766 Lancaster Co--), Nancy (1779-1867), Lydia (1785-1862), Matthew and Jane. Ann seems to have been the eldest.I've never heard of her marriage to Thomas, but the name Thomas Andrew Ramsey keeps cropping up later when the family moves to Ohio.
Sorry, this doesn't really answer your questions--if you have other Acheson/Reed questions I may be able to help. If you get answers from someone else I'd be interested in hearing about it.