My records are a bit confused on the Thomas branch. William C. MARLING of Pultney Twp, Belmont Co OH, had a son Thomas, b abt 1828, as shown in the censuses. A Thomas MARLING married 26 Dec 1849 in Belmont Co to M.J. Yocum, it seems. I have Thomas and Amelia married about 1851 and residing in Belmont Co OH for the rest of their lives. Amelia was at the County Infirmary in 1920. Her Ohio death certificate shows she died 3 Feb 1928, age 96y, 8m, 28d (b. abt 11 May 1831), but it does not list her maiden name, nor parents. There was another Thomas MARLIN in that area, born 1828 and died 1904, son of Jacob MARLIN.
Sorry that I cannot be more helpful. I am very interested in these MARLINGs and how they fit in.