First, no relation. However both David Jennings and his wife Harleston Simons Toomer Jennings were also from Connecticut. That’s where it ends.
The monument, head stones are nearby, was created in Zinc not stone and made in Bridgeport CT.
The site, and monument are clearly dated 1884. This is from a newer section of the old cemetery. Oh yeah, both of them were alive and well in 1884. Planning ahead I guess.
The 1860 Federal Census listed David as owning the large saddle and harness company on Meeting Street Charleston. He did not serve in the CSA army during the Civil War, likely he made saddles instead.
There are many graves in the family area, it was a large family. They had 13 children.
Even for the newer cemetery here this is a very elaborate burial site with a number of statutes and carvings.
The history of this family / monument was well documented.