Looks like her mother's maiden name is MInor:
John D. Johnson
mentioned in the record of John D. Johnson and Mary Elizabeth Minor
Citing this Record
"Kentucky Marriages, 1785-1979," database, FamilySearch(https://familysearch.org/ark:/61903/1:1:FWTY-XJQ : 11 February 2018), John D. Johnson and Mary Elizabeth Minor, 08 Sep 1856; citing Boyle, Kentucky, reference Pg154&155; FHL microfilm 191,806.
Kentucky Marriages, 1785-1979
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