Over the past years I have some updates that I can add to this post:
Mary Eva Wackenhut Kopp was married to George J. Kopp
Her siblings were; Anna married Andrew A. Jaeckle; Christine married John H. Pamplum; Karl married Marie Haas; Jacob W. married Mamie E.; and listed in obits as still living in Germany are John George and Marie.
I also found that for her husband George J. Kopp his sister Mary Anna Kopp married Chrisian Jaeckle who was the brother of Andrew Jaeckle who was married to Mary's sister. Some of the Jaeckle family lived in Rochester, NY.