Andrew Parsons / Kensington Palace Kate Middleton pulled out of a scheduled return to Royal Ascot on Wednesday, June 18 The Princess of Wales is said to be disappointed not to be able to join Prince William at the annual event Kate was initially listed on the carriage list for Wednesday when it was published Kate Middletonhas pulled out of a scheduled return to Royal Ascot. The Princess of Wales was set to return to the annual horse racing event withPrince Williamfor the second day of racing on Wednesday, June 18. She is said to be disappointed not to be able to join, but those close to her point out that she is still having to find the right balance as she works towards returning to public engagements following her treatment for cancer. Kate was initially listed on the carriage list for Wednesday when it was published. She was to have joined William in the second carriage. It has now emerged that he will be seated with his fatherKing Charlesand Queen Camilla. Her mother Carole Middleton was pictured arriving at the racecourse, which is just a few miles from Windsor Castle, at around 12.20 p,m. local time. Later, during the races, William is set to take on a special duty at the racecourse: presenting the trophy to the winner of the Prince of Wales' Stakes. The royal couple have been fixtures at Royal Ascot over the years, though last yearWilliam attended solo as Kate was undergoing chemotherapyfor an undisclosed form of cancer. He was seen mingling with members of the royal family as well as his in-laws, Carole and Michael Middleton. The Princess of Wales spent much of 2024 out of the public eye while focusing on her health, but announced in January that she is in remission and has begun a careful return to royal duties. Wednesday's outing follows a full few days for the couple. Over the weekend, they were joined by their children,Prince George, 11,Princess Charlotte, 10, andPrince Louis, 7, for King Charles's birthday parade, Trooping the Colour. They also stepped out Monday for the annual Order of the Garter service at Windsor Castle. Can't get enough of PEOPLE's Royals coverage?Sign up for our free Royals newsletterto get the latest updates on Kate Middleton, Meghan Markle and more! As Kate continues to ease back into public life, those close to the couple say they are taking a thoughtful approach to the road ahead. Queen Elizabeth's former spokeswoman Ailsa Andersonexclusively tells PEOPLE in this week's issue, "She's being sensible, listening to what her body is telling her and easing back into public life." Behind the scenes, the royal household is quietly planning for the future. With King Charles' cancer now described by aides as a "managed" condition, the Prince and Princess of Wales are preparing for an inevitable transition. "There are some major shifts coming behind the scenes," a friend tells PEOPLE. Read the original article onPeople