You are doing a great job presenting the novel to new readers. They should feel motivated to read it. I think that one if the reasons L'engle's novel was initially ejected was precisely because of the kinds of characters she created. She is uncompromising regarding gender or age or position. In the real world we have these kinds of hideous or just annoying people; some of them happen to be kids, or teachers or even parents.
But her story goes beyond that and questions all our philosophical assumptions regarding our world and our role in it.