Middle grade about a book where a girl discovers a book about monsters and the supernatural that belongs to her family

[Catherine]

The book is written from the protagonist's POV, who is a young girl. The girl and her younger brother go to a part of the house they shouldn't and discover a semi sentient book about monsters and the supernatural. The book bites the girl and she becomes sick but recovers quickly. Their father reveals that the book belongs to their family, is loyal to them, they are guardians of some sort. He warns them away from the book because of how young they are but the girl plans to read everything in that book. The children's mother is dead. Their father disappears or is kidnapped and it's up to the kids to stop the bad guys. I read an excerpt of that book on 2010. It has been translated into at least another language, Greek. Thanks in advance if someone knows it.

[Capn]

Endymion Spring?