She isn't merely Baumbach’s muse anymore or the star that mumblecore made. Her Mistress America takes its nominal origins from a brief scene in which Gerwig’s Brooke announces that the title would be her ideal superhero name, to which Kirke counters that “mistress” automatically connotes something lurid. But through her own ambition, artistry, and authority, Gerwig is helping to re-align the term “mistress” with its original and more powerful alternate definition. If anything, Gerwig is her own muse: inspiring, refining, and redefining herself, all while captivating the many modern-day moviegoers who feel lucky just to be here, right at the moment that she has arrived.