On ancestry.com there is a marriage in Georgia in Walton County of James S Thompson to Seletha Millsaps on 2 Jan 1840. I do not find any marriage for a Robert Thompson to a Sarah around 1885.
There is a marriage of a Martin Thompson to a Sarah A. Thompson in 1885, and R. W. Thompson to Etta B. Davis in Coweta County 25 Nov 1885
ancestry.com does not have death records for Georgia for 1900-1910.
familysearch.org doesn't have any matches.
> I am trying to find some information on Sarah Thompson [unk maiden name] .She is married to Robert S Thompson