LONDON — Kensington Palace launched an official picture of Catherine, Princess of Wales, on Sunday — her first since she stepped again from public view as she recovered from belly surgical procedure, an absence that has sparked frenzied hypothesis in latest weeks.The picture, of Catherine surrounded by her three youngsters, Prince Louis, Prince George and Princess Charlotte, was taken “earlier this week” at their dwelling in Windsor, a spokeswoman for Kensington Palace advised The Washington Put up on Sunday, and Prince William, Catherine’s husband and inheritor to the British throne, captured the second.