This book is awesome. A lot like Spiderwick, but longer and with a different writing style. I recommend it.
I’m about 3/4 of the way through it, and the imagery is nice and detailed. I think it might be a little scary for children younger than 6, but I think older than that, if a child has the ability to read a 359 page book, then they would love this one.
It has a healthy amount of lore, like the use of salt for protection and the insistence that faeries are amoral, and an interesting sibling dynamic.