My Sister's Keeper is almost two hours long—nearly as long as my quiet weeping jag lasted. So in many ways, director Nick Cassavetes (who previously made you guiltily sob through The Notebook) nailed the necessary pathos of a family's struggle with their teenage daughter's cancer. But the trials of terminal illness can be a bit like shooting fish in a barrel when it comes to jerking tears from an audience—so even while clutching your hanky, you may still walk away wondering if you actually liked this erratic film.

In a premise bristling with possibilities, 11-year-old Anna (Abigail Breslin) walks into the office of a lawyer's (Alec Baldwin) to sue her parents for medical emancipation. Anna was created in a test tube as a donor for her older sister, Kate (Sofia Vassilieva), who suffers from leukemia. Throughout her life, Anna has been harvested for blood and bone marrow, logging nearly as much hospital time as her sister. When Kate needs a new kidney, her mother (Cameron Diaz) eagerly volunteers Anna for the task—but Anna puts her foot down. The questions of body rights and legal issues concerning organ harvesting would make for a meaty enough topic—but it's dismissed in favor of watching the last remaining months of Kate's life, while her dogged mother fights tooth and nail to keep her alive.

There's much to recommend about the film: There are some good performances, including a pretty decent one from Diaz (her pig-headed, hysterical turn as she fights for her child's life is infinitely more tolerable than when she's trying to land a man in a romcom). All the wimpy crying is pretty cathartic, too. My Sister's Keeper—although an uneven and bumpy ride, pulls no punches when it comes to wringing out your tearducts—and if you feel like you've been emotionally manipulated, that's because, well, you have.