I would say it's targeted more for the 9-12 age range and her use of similes drove me crazy for a while but as I got into the book I forgot about it.
It follows a young man whose father disappears and he finds a hidden world living his younger brother to deal with the trauma in this world. It jumps straight into the action and never really stops as we follow the two brothers through the new world.
I did enjoy but took me a while to get into. Once I remembered it was for the younger audience it was easier to get involved in.