A couple of possibilities:
"Find A Grave Index," database, FamilySearch(https://familysearch.org/ark:/61903/1:1:QVGV-FDW5 : 13 December 2015), Janet Kay Keyes, 1995; Burial, Whittier, Los Angeles, California, United States of America, Rose Hills Memorial Park; citing record ID 124855612, Find a Grave, http://www.findagrave.com.
"United States Census, 1940," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:K9CY-H43 : accessed 16 December 2017), Catherine Keyes, Councilmanic District 11, Los Angeles, Los Angeles Township, Los Angeles, California, United States; citing enumeration district (ED) 60-893, sheet 10B, line 74, 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 410.
It does say "Montana", but that was also her last place of residence. Still possible it is her.