The Nun
La Religieuse (original)
In eighteenth-century France, a girl is forced against her will to take vows as a nun. Three mothers superior treat her in radically different ways, ranging from maternal concern, to sadistic persecution, to lesbian desire.
Starring Anna Karina, Liselotte Pulver, Micheline Presle, Francine Bergé, Francisco Rabal, Christiane Lénier, Yori Bertin, Hubert Buthion, Françoise Godde, Charles Millot
Watch "The Nun" on Kanopy released in 1967. It's a drama and romance movie, and has a rating of 7.5 out of 10 from Imdb which is usually fine for this kind of movie.