It’s not fair to describe British writer-director Andrea Arnold’s second feature as more or less Precious meets An Education, but it’s not wrong, either. Arnold’s vision is carefully calculated to bring the gritty with the pretty; she seems to want us to understand that even in the projects, teenage girls still swoon for white horses. It helps a lot to have the girl so magnificently played by nonpro newcomer Katie Jarvis, who holds the mostly handheld camera’s attention like her life depends on it. She’s a tough and tender 15-year-old, dreaming of stardom as a hip-hop dancer, sassing her boozy, floozy mother (Kierston Wareing) and crushing on mom’s troublingly receptive new boyfriend (Michael Fassbender). How moved you are by the hidden grace of getting by in the gutter probably will depend how well you tolerate a poignant/laughable late scene of mother and daughter coming to terms by dancing together to Nas’ “Life’s a Bitch.” For real.