Johann Georg Wechter (or George Wactor) did not marry Mary Magdalena Ott. He apparently arrived in South Carolina from Germany with a wife Magdalena (perhaps Mary Magdalena) and three children, but Magdalena's maiden name is not known. After George died, Magdalena remarried (on 24 June 1850) to John Frederick Ox, whose name has sometimes been mistranscribed as Ot or Ott. (It was probably originally Johann Friedrich Ochs.) This marriage is recorded in Rev. Giessendanner's parish register in Orangeburgh, South Carolina; he also served Amelia Township from time to time.
I've seen George and Magdalena's three children listed as William, Martin (or Marcus), and Abraham, but I don't know what the evidence for these names might be. I'm not really a Wactor researcher; I know about this family because I'm an Ott researcher, and this Ox/Ott confusion has tripped me up before.
Regards -- Mark James email@example.com