She is named on his death cert. at Ancestry.com. Didn't see it on FamilySearch.com, but they have census records for their household: 1910, 1920 etc.
Death record:
Ancestry.com. South Carolina, Death Records, 1821-1961 [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2008. Original data: South Carolina. South Carolina death records. Columbia, SC, USA: South Carolina Department of Archives and History. Citing: Volume #33, certificate #014436