The 1900 US Census shows that both of Sophronia's parents were born in Alabama.("United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M3TK-VGH : accessed 17 April 2016), Sofrona Prater in household of James F Prater, Township 2, Saluda, South Carolina, United States; citing ED 104, sheet 3A, family 38, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, n.d.); FHL microfilm 1,241,540.) Sofrona and James have been married for 15 years, but they are living in South Carolina, where James was born, so their marriage record could be either in Alabama or South Carolina. However, all their older children were born in Alabama, so the marriage record is probably in Alabama. Not much help there.
Some online trees (unsourced) show her maiden name as Tanner, but I cannot find any evidence to verify that.
