My DD10 just finished The Wednesday Wars and loved it so much she gave it to me for Mother's Day
If you like it, you'll like the follow up (it's not a sequel at all) Okay for Now. Both are EXCELLENT.
I just finished When You Reach Me; anyone from about 10 to 90 will enjoy it.
Cyntha Voight's books are great for that age (try Homecoming first), as are Katherine Patterson's (Jacob Have I Loved is probably her best). Marilyn Sachs is an oldie, but still read, I think, and deservedly so. Rita Williams-Garcia's book One Crazy Summer is really good.
Okay, that's enough realism.
Princess Academy and its follow up were both great, if she's into fantasy. I don't think anyone mentioned The Golden Compass series, which are really wonderful.
If you're on the edge with Hunger Games, you might try the Uglies series by Scott Westerfield. It's not quite as dark a dystopian world, maybe a half-step down, but very popular with the same crowd. (And the romance isn't as bad as it is in some of the current crop of dystopian teen novels that are swirling about ever since the Hunger Games.) Following in the Dystopian vein, there's the Maze Runner trilogy. (Not my cuppa, but well-regarded and a LOT of kids love them. They're filming the first book about 15 miles north of where I sit typing this, as a matter of fact!) Oh! And no one has mentioned Ender's Game, which isn't quite dystopian, but is science fiction, great for her age, and is being made into a huge movie (in Baton Rouge, which is south of me, LOL).
Luckily for me, all my younger dear relations have been readers at the age of 11 or so books are all we've ever had to buy them for forced periods of inactivity!