Mandatory Credit: Photo by REX/Tim Rooke (3210971ae) Catherine Duchess of Cambridge thin stomach Catherine Duchess of Cambridge visits the SportsAid Athlete Workshop, Copper Box, Olympic Park, Stratford, London, Britain - 18 Oct 2013 The Duchess of Cambridge has made her first solo appearance since giving birth. The new mum donned a nautical inspired outfit consisting of blue jeans, a blue and white striped top and matching blue blazer to visit a SportsAid Athlete Workshop at the Olympic Park in Stratford. And despite having to leave little Prince George behind, Catherine looked in great spirits as she laughed and joked with the young sports stars. She didn