In August you posted an obit for Maria's daughter which gives her burial info as: Fruitvale Chapel of the Clarence N. Cooper Mortuary, 1500 Fruitvale Avenue, Oakland. Interment, Mt. View Cemetery. Maybe Maria is buried there too or maybe the records for her daughter would give you a hint.
Clarence N Cooper Mortuary,1580 Fruitvale Ave, Oakland, CA 94601, (510) 533-4114http://mountainviewcemetery.reachlocal.net/index.html
Some possibles I found:http://ftp.rootsweb.com/pub/usgenweb/ca/alameda/cemeteries/m...
Mantz (blank) (blank) 5 S/W: Remmelhttp://ftp.rootsweb.com/pub/usgenweb/ca/alameda/cemeteries/m...
Wurthman Edith M. 0/0/1903 0/0/1935 56 S/W: Wurthman, Kathrine L.
Wurthman Grace M. 0/0/1869 0/0/1945 56 S/W: Wurthman, Edith M.
Wurthman Kathrine L. 0/0/1885 0/0/1926 56 S/W: MacKenzie, Kathleen A.
(abbreviation S/W = another name on the same marker)
Just a thought. Gena