In the novel They Do It with Mirrors, Fraulein Schweich is someone, probably a teacher, which Jane Marple, Ruth Van Rydock and Carrie Louise Serrocold remember from the days when they were girls together in a finishing school in Florence. There was something about Fraulein Schweich's boots which causes a great deal of amusement to the three friends.
Fraulein Schweich is also mentioned in the continuation short story The Mystery of the Acid Soil (this story is set before the time of They Do It with Mirrors. In Acid Soil, Miss Marple shares the joke about Fraulein Schweich's boots with Emmeline Strickert, another schoolmate from the days in Florence,