Dear Pekak,
It is hard to identify people in Germany 200 years ago. Let alone trace their descendants through all the persecution. Going by the most famous family/ies, they are still around and they are highly educated. It would be amazing if they did not know the history of their own last name. Which was a major part of nineteenth century Europe.
Are they Jewish? Who knows? Their ancestors were probably comfortable with where their children ended up. They advocated for assimilation, intermarriage, and even baptism.
But in general, we do not associate groups of Jews with children. It is about disciples and followers.