Susan was born in 1842. She is the daughter of Anthony Lightner.
Sources
"United States Census, 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M8DV-LLN : 12 April 2016), Susannah Sightner in household of Anthony J Sightner, Pocahontas county, part of, Pocahontas, Virginia, United States; citing family 179, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).