Queen Camilla spent her birthday on a royal tour of the Channel Islands, but King Charles will celebrate his wife’s big day once they’re back in London. “I think privately, the King will give her a party at Clarence House or Birkhall and they’ll have people go up to Scotland,” Paul Burrell said on behalf of Slingo. “He likes to give her jewelry. I think he’ll give her something special. He may have had something commissioned for a birthday.” “He’s very spoiling, the King, and he will make sure that all attention is on Camilla,”Princess Diana’s former butler added of Camilla, who turned 77 on J…