The father is either a demon or a superhuman prodigy, nothing strange about the daughter to inherit it.
Especially since we only know as much as her coming from the forest and "falling from the sky"
I am... just from that, Lotte is clearly not a normal child.
The father's quick change is suspicious, it makes me think he was aware of the book since he chunked it first into the fire.
Edit- Lottie is cute.