No, I have not found out where they are buried.
Stephen and Mary Laura both lived in Camden County, and MAY be buried in unmarked graves in Ceylon Cemetery but I have no proof.

James Jackson and Harriett Chesser Copeland were living in Horse Stamp, Camden Co. in 1880 and he died sometime in 1890.

Jesse died in Tattnall Co. in 1846-47. In 1870, Charlotte lived with her daughter, Sarah Saucer (Sasser).

I have looked but am unable to find the grave sites. If anyone has a suggestion, please let me know.