The film shows Kathe's mother and siblings moving to Monte Verita in 1908, but in real life she left Berlin in 1902 for Toskana and Ascona. They moved to Monte Verita first in 1904. Also, Maria's request to her father to bring her a doll happened in 1904.
The movie says that the copyright process between Käthe Kruse and the Bing Company lasted 7 years since 1919. However Käthe Kruse won the final process in 1925 at the Reich court house in Leipzig, which would be 6 years afterwards.
The Reich courthouse in Leipzig 1919 doesn't look at all like the real building. It is much bigger, has 6 columns instead of 4, no stairs at the entry etc.