Emma Horwitz’s new comedy, Mary Gets Hers, is a quirky coming-of-age story. Inspired by a 10th-century comedy, Abraham, by Hrosvitha of Gandersheim, Horwitz has retooled her work for contemporary audiences, with a lot of tomfoolery folded in, and director Josiah Davis, Horwitz’s long-time collaborator, has cast women in all the roles.