The lives of the royal sisters are affectingly revealed in Edwards's ( The DeMilles ) lengthy, crowded biography. Four years the elder, "Lilibet," born in 1921, was studious and responsible even as a child--different from the blithe, entertaining and musically talented Margaret. But the two were, according to the book, loving and mutually supportive. When their uncle, Edward VIII, abdicated, the girls' parents reluctantly assumed the monarchy. Upon the death of their father, George VI, Elizabeth inherited the crown and the sad duty of forbidding Margaret to marry Peter Townsend, evidently the one love of her life. The author quotes from private correspondence and persons involved with the royal family and describes Elizabeth II's wedding and coronation gowns and jewels in nearly numbing detail.