On Christmas Day, 1926, twelve-year-old Clotilde "Coco" Irvine received a blank diary as a present. Coco loved to write--and to get into scrapes--and her new diary gave her the opportunity to explain her side of the messes she created: "I'm in deep trouble through no fault of my own," her entries frequently began. The daughter of a lumber baron, Coco grew up in a twenty-room mansion on fashionable Summit Avenue at the peak of the Jazz Age, a time...