At age thirteen, she became Lady Diana Spencer. At twenty, Princess of Wales. At twenty-one, she earned her most important title: Mother. As she fell in love, first with Prince Charles and then with her sons, William and Harry, the world fell in love with the young royal family, Diana most of all. With one son destined to be King of England, and one to find his own way, she taught them dual lessons about real life and royal tradition. "William and...