What makes a coming-of-age movie work? Lord knows we get enough of them: overripe period pieces in which a filmmaker re-creates a precise cultural moment and his or her adolescent struggles with parents and injustice and best friends and sex. Usually, it comes down to the metaphysics of personal observation, which means the secondary characters can be well drawn while the protagonist remains an underwritten blank. It’s hard to see yourself when you’re looking through your own eyes.
That isn’t a problem in Sally Potter’s “Ginger & Rosa,” but only because Elle Fanning has the lead role of Ginger, a 16-year-old girl in 1962 London. Only 13 when the film was shot, the actress has a luminous naturalism that seems the opposite of performance: Emotions tumble forth from inside her, often in tight close-up, with a tremulousness that’s specific and real and heartbreaking. Where her older sister, Dakota, has the brazen skills of a born trouper, Elle’s acting feels artless and naive, and all the more powerful for it. Fanning easily convinces you of Ginger’s emotional reality — that every moment is the only moment.