She was living in Sedalia in 1943, and I found a SSDI entry that is a close match saying she died in March 1978 and last residence was Sedalia.
Born as Nancy Belle Amick in Tarkio, census records say she was born in Feb 1897. Family records say she was married to Alfred C. Smith. Her half-brother's obit from 1943 says he was survived by "Mrs. Clayton Smith of Sedalia".
I'd appreciate an obit, cemetery record or other information about her after 1943. Possibly the March/April 1978 area newspaper may have the obit.