If I'm able to raise a subject, get people uncomfortable about it, get them to ask the crucial questions," says Sharmeen Obaid Chinoy, "then I've done my job." In 2012, Obaid Chinoy became the first Pakistani to win an Oscar, with Saving Face, her documentary about brutal acid attacks on Pakistani women (often by a relative). The film was a testament to the power of the medium itself: It raised awareness on a global level, but also inspired grassroots aid—among other things, people donated homes for two of the women she featured. Now, with Humaira: The Dream Catcher, Obaid Chinoy is training her lens on a 24-year-old who, after her own father tried to stop her from finishing school in ninth grade, founded the only school in her neighborhood in…