Prince William and Kate Middleton are already preparing to someday take the throne following the death of Queen Elizabeth — one year ago this Friday. In addition to graduating to the titles of the Prince and Princess of Wales on the heels of the monarch’s passing, the couple, both 41, “are both involved in decision-making behind the scenes,” a friend of Middleton’s told People. “(King) Charles is leading the way for them already,” said the insider. “They are ready and willing to do the job — and Kate is very much a part of that.” Though insiders from the palace dismissed the idea that the newl...