Lady Boot teaches the Petit Ladies alongside Lady Lecter, primarily prepping them for upcoming tests. She goes by Lady Conductor as well, depending on the context.
You'll spot her instantly by her long, choppy purple hair and pinkish-purple eyes. She's basically always in a military-style outfit complete with hat—it's kind of her whole thing.
Unlike the typical prim-and-proper Lady, Boot's genuinely outgoing and optimistic, with a tomboyish streak that shows in how little she cares about proper etiquette. She loves going out in the rain, for instance, and actually dislikes parasols, which is pretty telling. She tends to pepper her speech with English words and isn't shy about cheering the Petit Ladies up when morale dips.
Content compiled by AnimeList.moe from publicly available sources.