Girl power means education. Research has shown over and over that investing in girls’ schooling pays big dividends. The movement even has an icon in Nobel laureate Malala Yousafzai, the Afghan teenager shot for insisting on her right to an education. But there’s a long way to go. Across developing countries, girls are still far more likely than boys to be kept from the classroom. A huge opportunity will come this September, when the U.N. is set to adopt its Sustainable Development Goals agenda — and prioritize young women and their collective future like never before.