I'm descended from that Spence family of Maryland & Delaware. My ancestor was Nathan Spence, born 1743 in Talbot Co. MD, but who lived in Kent Co. DE before & after the Rev. War (in which he served). In 1796, he purchased 500 acres on Reedy Fork Creek in Guilford Co. NC. By 1809, he was in Jasper Co. Ga., and he last shows up in Gwinnett Co. Ga. in several depositions he made re: his war service, the last of which is dated 2 Oct 1833 (when he was over 90 years old). I have scans of those original documents.
Although I have no proof of this, I strongly believe my Nathan was a great-uncle of your Ann Spence Chaffinch. Ann's grandfather James Spence (d. 1791, Northwest Fork Hundred, Sussex Co. DE) was (I believe) a brother of Nathan. Another presumed brother was John Spence (d. 1789, Sussex Co. DE) whose wife Nancy Quinnelly was probably a sister to Nathan's wife Elizabeth Quinnelly. That John Spence had a son and a great-grandson both named Nathan--presumably after his brother. The great-grandson was a lawyer in Muncie, Delaware County, IN. (He lived from 1838 to 1919). A whole bunch of the Spence relatives either went South, to NC and GA (my branch), or went North to Indiana. I've personally traced many of them.
I know very little about the Chaffinch part of the family, but wouldn't mind corresponding. E-mail me at firstname.lastname@example.org.
By the way, my youngest brother is named Nathan Spence White! My parents allowed me to give him his name. We are actually desc. twice from Nathan Spence--through his grandson McCalvis H. Spence (son of Nathan Jr.) who married his cousin Elizabeth "Betty" Spence (1812-1843), daughter of his uncle James Spence (son of Nathan Sr.). My uncle, cousin, and grandfather are/were all named Homer Spence White, and my grandfather's uncle was Charlie Spence Davis. We have always been proud of the Scots Spence surname!