You could try looking for the parents of Clara and William in her household in 1870
United States Census, 1870," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:M6L2-NQD : 12 April 2016), Anna Engert in household of John Engert, Ohio, United States; citing p. 32, family 247, NARA microfilm publication M593 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 552,763.
Maryland, Compiled Marriages, 1655-1850 [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2004.
some of the family trees on ancestry has this