Onscreen, Greta Gerwig’s whip-smart sensibilities and fearless vulnerability bring an easy authenticity to complicated yet beguiling characters. Offscreen, she has collaborated with the likes of Joe Swanberg, the Duplass brothers, and Noah Baumbach as a writer and a co-director (even while often still the star). Now, her feature directorial debut Lady Bird, starring Saoirse Ronan, is lighting up the festival circuit. Gerwig seems destined to keep dominating in the unique cinematic niche that she herself helped to create.