The following information comes from John Hensell's Abney books. Vol. I published in 1974, p. 99 and the Supplement, published in 1988, p. 110. The information should be treated as a starting point for research.
Sabina Abney married George Dean (born about 1783) on 9 Sept 1819; Sabina Abney being the daughter of John Abney (7 Feb 1761 Halifax Co., VA - 1812 Edgefield, SC) and Susan Pope. John Abney was the son of Nathaniel Abney (4 Apr 1734 Halifax, VA - 29 July 1806 Edgefield, SC), a brother of my Samuel Abney, Sr.
According to Hensell, George Dean was the son of George Dean. He was Heir-at-law of deceased brothers; sold their bounty lands to William Abney on 29 Dec 1788. George's other son was Absolom Dean who married Charlotte Malina Abney.
William Dean, the father of George, was born about 1734 and had besides George, Abney, Absolom and John. William Dean was granted land on Persimmon Lick Creek in Edgefield, SC (where Samuel and Nathaniel's brother Dannett settled) on 7 Oct 1786 which he sold to William Abney on 29 Dec 1788.
William Dean had a brother named Edward (born about 1719) who married Rebecca Abney. I have followed their son William Dean as he is the ancestor of a friend of mine. (I was able to get William Dean re-installed as a Revolutionary patriot so that she could join the DAR.)
The generations around the Revolution can become very confused. Often sons are shown in genealogies as grandsons or as sons of uncles. You have to be careful and look for proof if possible.