"... Anna Maria Geisler nee Brosch, Emilie Heutte nee Brosch, Clara Evert nee Brosch and Lina Lippman nee Brosch. The last three lived and died in Chicago. The first died in Milwaukee, Wisconsin in 1893 ..."

Any chance your Anna Maria Geisler was also a Magdalena? There are death notices in Milwaukee's German newspapers for a Magdalena Geisler in Nov 1893.

There are about 15 Brosch / Brösch and about 50 Geisler / Geissler entries or references found in "Milwaukee's German Newspapers; an index of death notices and related items" (1844-1950).
Gary Rebholz, originator/compiler/editor, Milwaukee Wis.
gary.rebholz@gmail.com
Indexing Milwaukee's German newspapers continuously since 2007... helping family researchers find their ancestors among Milwaukee's 99%.