She's also about to become the lead in an adult genre movie.
Most movies about kids feature kids acting like grown-ups. It's not just that casting is rarely age-appropriate—personalities are fully articulated in a way that is, frankly, wishful thinking, for both the teenagers in the audience and the former teenagers making the film. Capable and quick with quips, clearly defined in their tastes and attitudes, kids and teens in the movies—even in movies that are ostensibly about the process self-discovery—rarely reflect the retrospectively embarrassing anxiety of influence you and I mostly associate with childhood and adolescence.
One way movies do this—flatter children, and memories of childhood—is by making kids the protagonists of genre movies. Of road movies, sports movies, screwball comedies, action movies. Genre is structure—it's a matrix of plot circumstances and behaviors, and by placing adolescent experience within genre structure, we give that experience clarity and meaning. Sometimes movies know this—I love the self-consciousness of Brick, a noir movie set in high school.
Winter's Bone is another teenage noir, sort of. Ree has to find her father, or lose her family's house, of which she is the de facto head, though her autonomy—or "agency," as we say—is rather tenuously clung-to. So she travels through her extended family of crank-cooking Ozark cousins, which doubles as a criminal underworld, stirring shit up. But just as she's in danger of losing her house and family, she's in danger of not being taken seriously as a noir heroine. Her knowledge of the family business is circumscribed at best (the film, told entirely from Ree's point of view, does a great job of letting her, and us, know just enough), and she struggles to get an audience with the local boss (for a time, her uncle has to stand for her). I think of those early scenes of Ree looking in on Home Ec and JROTC as a passkey for the movie: for one thing, it's making Ree into an adult by putting her into some adult (movie) situations—interrogations and and beatings and seedy dives and hard truths. For another thing, it's demonstrating how Ree's different from most teens, and their movies, which are just playing genre dress-up.