I am not connected to these persons, but I found a Georgia Marriages index record on FamilySearch.org for Thomas J Stitt and C P Allman, 16 Nov 1865 in Troup County, Georgia (
https://familysearch.org/pal:/MM9.1.1/FWCP-25B). I do not know how you would go about requesting a copy of the certificate.
Also, FamilySearch.org has an Alabama Deaths and Burials, 1881-1974 index record for Mrs Tom Stitt, 8 Dec 1915, Wehadkee, Randolph, AL (
https://familysearch.org/pal:/MM9.1.1/F3YY-LXH). I did not find a death record for her husband. You can request a copy of Mrs Stitt's death certificate through Wallace State Junior College Genealogy Dept in Hanceville, AL. There is a small charge. Telephone is 256-352-8263.
Good luck with your search.