Stepfather is listed as father

My grandmother's stepfather is shown as her father. How does this get fixed? Sarah Louanza Turbeville was first married to Henry Evans/Ivins Stone (14 March 1886 Clark Co., AR). They had three children. Henry died on 20 October 1900. Sarah married William Pressley Harper and together they had Dona and Leroy Harper. My grandmother, Willie Mae Stone Throgmorton, was born 7 March 1896 in Clark Co. Arkansas. FamilySearch sends me birthday reminders, etc. of the Harpers, but not the Stones.