Prince William “stepped up to the mark” in the absence of King Charles. The 41-year-old royal has helped to fill the void while the monarch – who recently returned to public-facing duties – and his wife, the Princess of Wales, have undergone treatment for cancer. Royal photographer Samir Hussein told Us Weekly: “I think it remains very positive that Prince William has really stepped up to the mark with the king being out of action for a few months.” Samir praised the Prince of Wales for how he’s dealt with the situation. He said: “Prince William’s been through so much, obviously, with what’s b…