Hi! If you go with the other poster's info, that Joe and Nona are brother and sister (which I agree, that's your Joe), then Nona has a death certificate with parents listed.
Nona Paralee Bass father: J. D. Hallenquist mother: Ella Duffey birth: April 29, 1895, Place of birth: Texas POD: (Hospital) Mt. Vernon, Franklin Co. TX DOD: March 17, 1971 Burial: Perryman Cemetery, Wood. Co.