What are some supporting characters in Wrinkle in time?

In "A Wrinkle in Time" by Madeleine L'Engle, several supporting characters play crucial roles. Mrs. Whatsit, Mrs. Which, and Mrs. Who are three celestial beings who guide Meg Murry and her companions on their journey through space and time. Additionally, Charles Wallace Murry, Meg's exceptionally intelligent younger brother, provides both support and unique insights as they face various challenges. Calvin O'Keefe, a friend of Meg’s, also joins the adventure, bringing his own strengths and perspectives to the group.