Watch: Kate Middleton Steps Out in Enormous Tiara for State Dinner With Prince WilliamPrincess Charlotte is stepping into some very big shoes. The 10-year-old daughter of Prince William and Kate Middleton joined her parents-along with siblings Prince George, 12, and Prince Louis, 7-for the Together At Christmas Carol Service at London's Westminster Abbey Dec. 5, where she donned an ensemble that evoked her late grandmother Princess Diana. During the royal outing, Charlotte stepped out in a velvet long-sleeve navy blue dress with a white collar, along with navy tights and a pair of dark flats.