Speaking German...
Does anyone else not think it a little unusual that Nancy is able to speak German so fluently to Stefan? She is only 19 (from her gravestone) and her background is that she was raised in an orphanage so it is unlikely she had a classical education or teacher training.
Plus, to be honest, it is 1943, anyone who can speak German would likely be keeping very quiet about it as there would be a danger they might be thought a spy (especially if they were a recently arrived stranger in a rural area).
I prefer Imaginality to reality.