Britain's Prince William, Duke of Cambridge, carries his newly-born daughter, his second child with Catherine, Duchess of Cambridge, as they leave the Lindo Wing at St Mary's Hospital in central London, on May 2, 2015.  The Duchess of Cambridge was safely delivered of a daughter weighing 8lbs 3oz, Kensington Palace announced. The newly-born Princess of Cambridge is fourth in line to the British throne.   AFP PHOTO / POOL / JOHN STILLWELL        (Photo credit should read JOHN STILLWELL/AFP via Getty Images)