That statement never made sense to me as I had located marriage records for other couples who married in St. Louis during this time period. When I looked for the marriage myself, using the approach that would have been done in 1890 when this affidavit was made out, I realized why it was not located.
The marriage of Wilhelmina and her husband did take place in St. Louis, as she insisted, however. The problem was that the marriage was not indexed in the record book in which it appears and the clerk apparently did not take the time to search the record book entry by entry.
There's more about the location of this marriage record in a Rootdig.com blog post "Finding Wilhelmina Trautvetter's 1851 Marriage Entry."
There's a few other issues about Wilhelmina that we are working on for an upcoming newsletter issue. Stay tuned.