Prince William is set to make a special appearance at the landmark Diana awards. The event will mark the 25th anniversary of the Diana award, which celebrates the achievements of exceptional young leaders. The Prince of Wales will attend the awards on Thursday at the Science Museum in London. At the event, William will meet with key staff and supporters of the Diana Award and then join a ceremony to hear about recipient’s work. The awards were set up in memory of Prince William’s mother, Princess Diana, and her “belief that young people have the power to change the world.” The Diana Legacy Awa…