THEY WERE THE HAPPIEST, I PROMISE. They just grew old and died of old age; they had normal, fulfilling lives, and Grace helped reconcile her feelings with the memories of Narnia so they totally both got to visit Narnia, show up everybody but Lucy (who always knew Susan would come back to them; Lucy is faithful, always), and then cruise into heaven looking like the fabulous queens they were.
Re: PART TWO; Because I can salvage this, I swear.
THEY WERE THE HAPPIEST, I PROMISE. They just grew old and died of old age; they had normal, fulfilling lives, and Grace helped reconcile her feelings with the memories of Narnia so they totally both got to visit Narnia, show up everybody but Lucy (who always knew Susan would come back to them; Lucy is faithful, always), and then cruise into heaven looking like the fabulous queens they were.