I have some information on the Margaret Snider and Ruhama Sea, but I have no source material. This is all from family history, and I haven't had time to check its accuracy. Hope it's a starting point.
Margaret Snider's father was Hans Jacob Schneider who was born February 13, 1742 or 1743, location unknown. He died in 1814 in Dutch Fork, South Carolina. I do not have any further information about his family.
Margaret Snider's mother was Susanna Oswalt, born about 1750 in South Carolina and died after 1830 in Tuscaloosa County, Alabama. I don't have her parents' names, either.
The couple married about 1761 in Lexington County, South Carolina, and Margaret Snider was born about 1767 in Lexington County, South Carolina.
Margaret married Nicholas Sea, date unknown. Nicholas was born about 1765 in Lexington County, South Carolina. He died November 1829 in New Orleans. I have his mother listed as Sophi Puhl, born about 1731 in South Carolina.
Margaret Snider died about 1814 in Lexington County, South Carolina.
Ruhama Sea was born in August of 1812 in Lumberton, North Carolina. She married James Atkinson about 1829, (also from Lumberton) and they had at least one son, Clinton Atkinson, born in 1832 in Columbia, Mississippi.
Ruhama died September 27, 1886, in Columbia, Mississippi, and her husband, James, died in 1849 in Hinds County, Mississippi.
I am a descendent through the Atkinson line, but from your note, I see that Ruhama Sea married twice. As I said, hope it helps. Let me know if you find anything new!