(Research):https://www.findagrave.com/memorial/161164776/dorothy-may-palmer
"United States Census, 1920," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:M6QL-MLP : accessed 10 May 2020), Dorothy M Barnes in household of Bertha M Banes, Frederick, Frederick, Maryland, United States; citing , sheet , line , family , NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 672; FHL microfilm 1,820,672.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:X34N-5F3 : accessed 10 May 2020), Dorothy M Barnes in household of Charles R Barnes, Frederick, Frederick, Maryland, United States; citing enumeration district (ED) ED 9, sheet 5B, line 51, family 108, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 874; FHL microfilm 2,340,609.
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K7F4-PY5 : 29 November 2019), Dorthy M Barnes in household of Charles R Barnes, Frederick, Election District 2, Frederick, Maryland, United States; citing enumeration district (ED) 11-18, sheet 11B, line 78, family 246, 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 1548.