The late Diana, Princess of Wales, is as irresistible a book subject as ever. A recent offering, Diana: Her Life in Fashion (Rizzoli, $40, 0847821374), is a tasteful, serious look at her transformation from innocent nanny to independent philanthropist as interpreted through her wardrobe. The author, fashion editor Georgina Howell, invited Diana's fashion designers and personal contacts to reflect upon their roles in Diana's evolving style and share special memories and insights. Fittingly, the book is liberally bedecked with gorgeous photographs and official portraits. All royalties from sales of this book go directly to the Diana, Princess of Wales Memorial Fund.