I looked up Charles D.Ault on the 1930 census and the famly is in Calvert Twp, Grant Co. Arkansas. But you probably knew that. The census lists the birthplace of Charles' father & mother as Ohio. I searched the 1880 indexed census on familysearch.org for a Charles born about 1879 in Indiana and the only one that was close was listed as 2 years old on the 1880 census in the household of a James W. Ault in Jackson, Greene Co. Indiana. This James W. was born in Ohio. The LDS IGI records have a Charles Ault b. July 17, 1877 Greene Co. IN to James William Ault & Sarah DeNiza Emery. Could this be your Charles D. Ault? On the 1880 census, the wife listed with James W. Ault is a Rebecca, not Sarah. Could this be the step-mother? The only problem is this Charles Ault died Aug 7, 1964. Are you sure of the death date you have for Charles D.?