Kate Middleton Sparkles at Friend's Wedding Kate Middleton, Duchess of Cambridge, was among guests at the wedding of Thierry Kelaart and Patrick Heathcoat-Amory, at St Bartholomew's Church in Oxfordshire, England Sept. Kelaart is a close friend of Middleton's sister Pippa. The Duchess wore a light blue dress by Erdem. The dress is the same one she wore in June while attending festivities to mark the Queen's Diamond Jubilee. (Ikon Pictures Ltd.