I spotted a movie mistake!
Sorry, I shouldn't be happy about this (especially since I liked the movie a lot), but having always been teased for my lack of observation skills I'm just proud I spotted it. So here it goes: at the beginning of the movie we are informed that this is Copenhagen 1926, but a bit later in the movie, when Gerda opens the letter from the first doctor that examined Elbe/Lilly, it is dated 1925.
~*~