Gertrude (ガートルード Gātorūdo) is a senior aide in the Eiserne Jungfrau, and a first-class priest. She wears a uniform similar to Cornelia's. Like her comrades, she appears extremely deadpan when on duty, but is actually a very charitable character well-liked by her juniors. Gertrude is able to create powerful barriers, with only one known instance of being broken. She serves as Furniture, along with the rest of the Eiserne Jungfrau, to Erika Furudo and the Witch Council.
- She has a tendency to say "Allow me to speak." and "Let it be said that..." before declaring a statement in the Red Truth.