Photo of John Engelhorn with wife and young son
Census records show many Englehorns in Lansing, Allamakee, IA in 1870. All are listed as born in Baden. Their ages suggest they could be siblings and children of Anna's husband.
Bio at Roots Web http://www.rootsweb.com/~iaallama/BIOS/engelhorn_j.htm
See also the Engelhorn Family webpage http://www.theengelhornfamily.com/
Bio of John Engelhorn at Engelhorn Family webpage http://www.theengelhornfamily.com/familytree/john01.htm