I reveiwed you message history and found her name. I see them in the 1930 Palo Pinto census, ages 53 and 50. Could this Bell be your Belle? You didn't give a death date.If this isn't her, then maybe she died out of state therefore the state wouldn't have the death certificate.
Texas Death Indexes Morgan, Bell - Tarrant County, 3-12-32, #13895 Morgan, Clifton C - Erath county, 7-4-39 #32624