Britain's Prince William, Duke of Cambridge (R), and his son Prince George of Cambridge wave as they return to the Lindo Wing at St Mary's Hospital in central London, on May 2, 2015 where his wife Catherine, Duchess of Cambridge, gave birth to their second child, a baby girl, earlier in the day. 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 / LEON NEAL / AFP PHOTO        (Photo credit should read ISHARA S.KODIKARA,LEON NEAL,JUSTIN TALLIS,BEN STANSALL/AFP/Getty Images)