Sister Mary Eucharist was one of the nuns who accompanied Sister Mary Augustine to the hospital in Damned If You Do. She was portrayed by actress Lucinda Jenney.
Unlike Sister Mary Pius, Eucharist was sure that Augustine's raw and bleeding hands were the result of an organic illness instead of stigmata. However, as she waited in the chapel, she met Gregory House. House offered her some chocolate which she quickly accepted. Eucharist told House that Augustine was a malingerer and that the Mother Superior frequently let her out of her duties. It was clear to House that Eucharist resented Augustine, and he reminded her that envy and gluttony were both sins. Eucharist countered that she hoped House wasn't as miserable as he seemed.