Spoilers below, it is a pretty good series, read it. But also, do not start with the Magician’s Nephew. It is chronologically first, so some publisher changed it after the author died, use the original order.
Tap for spoiler
Spoliers
She was a queen of a long dead world with a dying sun, and had gone into a magical stasis. The children inadvertently woke her and brought her to Narnia as it was being created. But Aslan is much older than her. It isn’t stated outright, but he may well have created the world she was born on too, if there are other world makers they aren’t mentioned
.
If your set starts with the Magician’s Nephew, move it to second from last. Read The Lion, the Witch, and the Wardrobe first. The Magician’s Nephew is chronologically first, but the wrong order to tell the story. Which is why the author didn’t put it first.
It all makes sense if you read Magician’s Nephew first, but it removes mystery from the others. And the reveal of the events in Magician’s Nephew was more exciting after reading most of the rest of the series, instead of being the intro to that universe. It takes some of the magic out of the series. As someone who has read most of C.S. Lewis’s books more than once, I’m pretty confident he’d be pissed about it.