

Britain's Prince William and his wife Catherine, Duchess of Cambridge attend a reception at Centrepoint's Camberwell Foyer in London on December 21, 2011. The national charity Centrepoint provides housing and support to improve the lives of homeless young people aged 16 to 25. Ben Stansall/Reuters
From left, Lauren Harper, Prince William and Catherine, the Duke and Duchess of Cambridge, and Prime Minister Stephen Harper watch a children's sheep riding event at the Calgary Stampede, July 7, 2011, in Calgary, Alberta. Jonathan Hayward/The Canadian Press/AP
Britain's Prince William, Duke of Cambridge and his wife Catherine, Duchess of Cambridge, attend a 'healthy living cookery session' during a visit to Centrepoint's Camberwell Foyer in London, Dec. 21, 2011. Ben Stansall/AP
Tiffany Steppacher of The Cupcake Lounge in the Byward Market prepares a cupcake display in preparation for the royal visit of the Duke and Duchess of Cambridge in Ottawa, Canada, June 29, 2011. Sean Kilpatrick/The Canadian Press/AP
Prince William and Catherine, the Duke and Duchess of Cambridge, arrive in Calgary, Alberta, as they continue their royal tour of Canada, July 7, 2011. Charlie Riedel/AP
Prince William, in blue shirt, and his wife Catherine, standing, compete in a dragon boat race in Dalvay-by-the-Sea on Prince Edward Island as part of their Royal Tour of Canada, July 4, 2011. Robert F. Bukaty/AP
Prince William and Catherine take part in a ceremonial tree planting as Governor General David Johnston (r.) and his wife Sharon watch at Rideau Hall in Ottawa, Canada, July 2, 2011. Nathan Denette/The Canadian Press/AP
Britain's Prince William (l.) and Catherine, Duchess of Cambridge and Prince Harry (r.) leave the VIP marquee during a military awards ceremony, A Night of Heroes, at the Imperial War Museum in central London on December 19, 2011. Arthur Edwards/Reuters
William and Catherine (r.) watch a dance show by teenagers during a visit to the Inner-City Arts club in Los Angeles, California, July 10, 2011. John Stillwell/Reuters
From left, Britain's Prince Andrew, Prince William, Prince Charles, Catherine, Duchess of Cambridge, Camilla, Duchess of Cornwall and Prince Harry arrive to attend a Christmas Service at St Mary's church on the grounds of Sandringham Estate, the Queen's Norfolk retreat, England, Dec. 25, 2011. Lefteris Pitarakis/AP
Catherine Duchess of Cambridge (c.), Camilla, Duchess of Cornwall, (l.), and Sophie, Countess of Wessex during the service of remembrance at the Cenotaph in Whitehall, London, Nov. 13, 2011. Queen Elizabeth II and other senior members of the royal family were leading the annual Remembrance Day ceremony in central London to honor the nation's war dead. Kirsty Wigglesworth/AP
Th Duchess of Cambridge receives flowers and a card from a girl after she and other members of the royal family attended the Christmas Service at St Mary's church in the grounds of The Sandringham Estate in northeast England, Dec. 25, 2011. Lefteris Pitarakis/AP
The Duke and Duchess of Cambridge walk hand in hand from Buckingham Palace in London, April 30 2011, the day after their wedding. John Stillwell/AP
A Spitfire, a Lancaster Bomber and a Hurricane fly over the crowds gathered on the Mall, in front of Buckingham Palace, after the royal wedding of Britain's Prince William to Catherine, Duchess of Cambridge at Westminster Abbey, in central London on April 29, 2011. Prince William married his fianceé, Kate Middleton, in Westminster Abbey. Oli Scarff/Reuters
William and his wife Catherine, Duchess of Cambridge kiss on the balcony of Buckingham Palace, following following their wedding at Westminster Abbey in London on April 29, 2011. John Stillwell/Reuters