Free from the shackles of the ill-fated How I Met Your Dad, Greta Gerwig can go back to doing what she does best: Working with director Noah Baumbach, who directed her in Greenberg and Frances Ha. As with Frances, the two co-wrote Mistress America, which debuted at Sundance and opens next Friday. Lola Kirke (Gone Girl, also sister to Girls’ Jemima Kirke) co-stars as an unhappy college freshman who is jolted out of her lonely existence by her soon-to-be-stepsister (Gerwig).