For anyone researching this Milwaukee family, there's a notice in the German newspapers for the Siegel/Schläfer family - and it's not a death notice (?!?) but a German Consulate query. There is also a death notice for Catharine published in these papers and many other Siegel entries.
"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 ... it's about German-American culture, not data.