At 15 years old, Avery is a bright, gorgeous, gifted athlete who is very much loved by her white Brooklyn Jewish lesbian mothers. She’s also black, has a trans-racial older brother at Princeton and a younger one who was born in Korea, both of whom she adores. Bearing in mind that we all turn our best faces to an inquiring camera, this is as happy and well-adjusted a family as you could hope to find—until Avery, struggling to claim her African-American roots, sets the cat among the pigeons by contacting her birth mother in Texas. A lesser filmmaker than Nicole Opper might use this emotionally freighted scenario to address the Question of the Lesbian-Headed Family or set an identity-politics agenda. Instead, like the best documentarians (she trained with Macky Alston, whose terrific film, Family Name, explored his own biracial family tree), Opper knows how to listen, watch, wait, and build a picture as close to her subjects’ points of view as can ever be achieved by an outsider setting up shop in a private home. Race and identity figure, but immanently: Off and Running is a tactful but probing and richly satisfying study of an entire family thrown into self-doubt by a teenager venturing into risky territory as she struggles to find her way. Opper doesn’t angle for a climactic group hug, but she sticks around long enough to allow us to exhale while this intelligent young woman begins to set herself, quite literally, back on track.