Kristen Stewart, 19, with her bedroom eyes, long limbs and melodic voice, is some kind of passionate forest sprite — one studly young men are always tearing themselves away from deflowering. In 2007’s “Into the Wild,” Stewart is one of several characters who meets the main character as he’s setting out on a foolhardy and ultimately fatal trip to the Alaskan wilderness. He leaves them all for his solitude — but when he leaves her, a guitar-playing runaway who can strip off her shorts in half a second, the audience gets it. OK. He really is nuts.

And she ticked off the deep-role-in-the-critically-acclaimed-drama box.

In “The Cake Eaters,” Stewart, as 15-year-old Georgia, proves she’s capable enough to play someone with a physical disability — in this case, a nervous system disease that leaves her a pigeon-toed lurch and the coordination and slur of a lush on a choppy sailboat ride. The best part about the movie is that, leaving behind all the other sub plots and filler, Georgia is less interested in her mom’s portraits of her (to raise awareness of the disease! says her mom, who would rather see her in a wheelchair) and — far more realistically — just wants to get laid before she’s too twisted. And, realistically, she’s no perfect heroine. Once she finds the guy, seeing him shirtless for the first time, in casual conversation she remarks that he must not work out a lot.