Sister Correda is a teacher at Saint Michael’s School. She is the nice but scatterbrained first and second grade teacher (The Curse of the Blue Figurine, 65).
Inspiration[]
While it’s possible it could be used as a real name, correda seems little more than an echo for corrode.
The sister's name is similar to Sister Coroda, one of the instructors at the Catholic women's college. It is unknown whether Bellairs had a teacher with a similarly-sounding name since it appears twice in his writings.