I think I have found the family you are looking for--but there are some differences. I find nothing to show that Sula was Cherokee. She was daughter of Edmund Vaughn & Mary Caroline Morgan. Edmund goes back to SC then VA. By 1850 the Vaughn family was living in Wingo, Graves County KY. On the same census you can find the Lynch Family.
John S & Sula m. 1893 and in 1900 were still in Graves CO., KY 1910 they are in Hickman Co., KY. 1920 in Dyer Co., TN 1930 living with son William & family in Wayne Co., Michigan. Sula d. 1939 and John d. 1950, but can't find location or where they are buried. Believe --from Census records--- they had 10 children. Could find nothing linking him to Methodist Church. Could find no record of other wives.
Tennessee State Marriages, 1780-2002 about Miss Sula Vaughn Name: Miss Sula Vaughn Spouse: J S Lynch Marriage Date: 8 Jan 1893 Marriage County: Obion