In 2013-2016 we designed and implemented Wikid Grrls, a 10-week after-school workshop series to teach online skills to middle school girls in U.S. schools. We interviewed and surveyed 80 participants before and after the workshops. Girls' online skills and confidence in them increased measurably for the duration of the workshop series. Participants expressed great interest in learning more, but media literacy programs at their schools regarding online skills were lacking. Using feminist theories and the reader-to-leader framework, we argue that such media literacy interventions bring immediate learning rewards for participants. Yet, we conclude that to narrow gender gaps in digital knowledge creation and sharing, media literacy classes that include online skills should become regular features in U.S. school curricula instead of being offered merely in voluntary programs. Future research should assess long-term benefits of media literacy interventions to teach online skills longitudinally to see if and how such initiatives figure into later school and career decisions.