There is a very long obituary for his brother Andrew John Kauffman in The Settlement of Germantown, Pennsylvania... which is a free ebook. According to that article Clara had a brother C,C. Kauffman who was also a politician.
There is also a biographical sketch of someone name Levi Kauffman at http://files.usgwarchives.net/pa/cumberland/bios/beers1886/kauffman-levi.txt
I didn't read the whole thing but it looks like Levi is his brother or father.
And here is the 1880 census for the family
"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MWFT-68N : 10 August 2016), Clara Kauffman in household of C S Kauffman, Columbia, Lancaster, Pennsylvania, United States; citing enumeration district ED 127, sheet 107C, NARA microfilm publication T9 (Washington D.C.: National Archives and Records Administration, n.d.), roll 1141; FHL microfilm 1,255,141.