Okay, okay, this 2006 film is not originally German, BUT it IS the film adaptation of Cornelia Funke’s book of the same title, and of course her book was originally in German.
The Thief Lord is a nice film with a feel-good ending, which makes it more of a “movie to relax with” than most German films.
This film is rated PG in the U.S. It would make a good book/film comparison unit. There are many scenes with a “Something Wicked This Way Comes” feeling, which may lead to a good cross-curricular connection.