The names of the 4 children were surely not chosen at random. Peter is a natural choice for the chief vicegerent of Aslan/Christ, as is Lucy for the youngest child who yet enlightens the others about the existence of Narnia (before the 16th century reform of the calendar, St Lucy’s day was the shortest, while her name, of course, means light).

Why is Susan chosen for the one who is eventually excluded? Because Susannah was excluded from the Protestant canon? I wouldn’t put it past him!

That leaves Edmund. I have no clear idea why this was chosen. To English ears the name has a chivalric sound. Possibly it was intended to suggest the insufficiency of natural virtue.