Dear Ms. Greene,
Thank you for posting your request on History Hub!
We suggest that you contact the St. Charles County Recorder of Deeds, the St. Louis County Recorder of Deeds and the St. Louis City Recorder of Deeds to request a search for their marriage certificate in Missouri. We also suggest that you search the Illinois Statewide Marriage Index, 1763–1900 and then contact the appropriate Illinois County Clerk for their Illinois marriage certificate.
We hope this is helpful. Best of luck with your research!