I started out with a nice simple book, The Graveyard Book, by Neil Gaiman. She read it -- not to my surprise, she loved it -- we discussed it, with me luring out the main metaphors and themes -- she wrote a paper, she did a presentation.
Now we're reading The Hunger Games, by Susan Collins. Why did I choose this text? Obviously I was INSANE.
I had read it myself, over the summer, both it and its sequel, Catching Fire, and I knew it was an engrossing book, right up the kid's alley so far plot and such. She'll love this, I thought.
And man, does she.
But OTOH -- wails of grief, demands that I come comfort her when something wretched is happening to the characters (but I can't tell her that things are going to get better -- "No! Ma! No SPOILERS!"), sobbing fits when something awful has happened.
If you're thinking of giving this book to your sensitive twelve year old? Maybe not.