When the children arrive at the old professor's house, it's big and full of ancient artifacts. Mrs. McCready is clearly devoted to the professor, but she doesn't know the side of him we come to know: that of Digory, the boy who was there when Narnia was created. It seems her main job is to protect the dignity of the house and its owner, and that doesn't include relating to the children's sense of wonder at all.
The professor's name is Digory Kirke. Kirke = Church. C. S. Lewis uses this play on words in another book, "The Pilgrim's Regress," in which "Mother Kirk" represents The Church.
So a child's first impression of the Church is that it is large, imposing, fascinating, untouchable, and not a most welcoming place. It has gatekeepers, like Mrs. McCready, who have little or no imagination and who serve only to protect the institution.
But hidden away in it somewhere is a wardrobe: the door to a world that is much bigger on the inside than on the outside. The trick is to get curious enough to find it!
