Alice Watson married Samuel Epstein on 8 Nov 1911 in Grant County. You see them in the 1920 and 1930 censuses with her children Icy and Keller Watson.
The Marion library database shows no death or cemetery records for them, but does show obituary records. Samuel has 2 obituaries in 8 Apr 1930 newspapers, so he probably died Apr 7th. Alice has obits on Nov 6th & 7th, 1958, so she probably died Nov 5th.
You can order copies of the obituaries from them, and it will most likely mention the day they died.