Character Analysis
Sister Leopolda is the sadistic nun who tortured Marie when she was a young girl and drove her from the convent (and her aspirations of sainthood). She seemed to actually think she was doing Marie some good with her nasty behavior by driving the devil from Marie's mind/body. For example, one day, she decided to pour boiling water over Marie to chase the Devil out, declaring, "I will boil him from your mind if you make a peep… by filling you your ear" (2.1.60). Charming and sane behavior: that's our Leopolda.
Even though she seemed physically frail, she was tough and scary. In Marie's retelling, "Her fingers were like a bundle of broom straws, so thin and dry, but the strength of them was unnatural" (2.1.27). She retained that combo of a brittle appearance and iron grip well into her later years, when Marie went to visit her… and found her to be just as evil and cantankerous as she always was.