Looks like Johanna married a second time to Elmer Bauer.
"United States Census, 1940," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:K7VH-QR8 : accessed 2 August 2017), Johanna Bauer in household of Elmer Bauer, Ward 4, West Allis, West Allis City, Milwaukee, Wisconsin, United States; citing enumeration district (ED) 40-103, sheet 3B, line 78, family 68, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 4504.