It was compared to "The Lovely Bones" on the cover of my version, and in some days it has a similar feel - the characters feel trapped and desperately unhappy and a teenage daughter dies for a reason the reader cannot fully grasp until near the end. I would argue that if you take out the sexual abuse aspect it reminds me more of "The Diary of Laura Palmer", but it isn't really either of these books and deals with many things the above named books do not touch on.
In a nutshell, for me the book was about a family of five who want different lives. They stagger around the house together (emotionally not literally), leave each other bruised at times, but are unwilling or unable to communicate the reasons for their unhappiness.
It's set in the 1970s in a small American town. The father James is Chinese. The mother is white, and the children rather obviously are mixed race. For a variety of reasons none of them really fit in to the community, and all of them are lonely in spite of their love for each other. The parents, for reasons that would require a spoiler so shall not be explained here) pour all their energy and hopes into Lydia, the middle child and elder daughter.
Hannah is the youngest, born to late to have shared the trauma of her elder siblings, but not immune to its aftermath. She hides, watches and listens, and from clues she picks up along the way sees more accurately than the others the danger the family faces.
It's beautiful, poignant and sad. The language is simple enough to appeal to a young adult audience, while the ideas expressed are complicated enough to appeal to mature adults. I loved it, as you can see by my rating.