During an AMA (ask me anything) on Reddit, Swinton was asked if she would reprise her role in any sequels. She answered:
I have always hoped that there would be the chance to make THE MAGICIAN’S NEPHEW.. the prequel to THE LION THE WITCH AND THE WARDROBE – such a fantastic story.. the creation of Narnia and the Witch driving a coach and four horses around Victorian London at breakneck speed.. but no word as yet.. let’s cross our fingers..
Count us among those that want to see that happen sooner rather than later. I’m hopeful that this doesn’t lead to her playing the role of the Lady of the Green Kirtle in The Silver Chair, but who knows.