In case it's helpful to your research, the family placed death notices in the local German newspapers for Wilhelmina Schulz Thomas. These aren't obituaries but usually include immediate family.
There's a Thomas/Schultz marriage certificate online in the public library digital collection.
"Milwaukee's German Newspapers; an index of death notices and related items" (1844-1950).
Gary Rebholz, compiler/editor
Indexing Milwaukee's German newspapers continuously since 2007... helping to access our historic German-American culture.