See the first official photo of Kate Middleton since she announced she had cancer

Other senior royals confirmed to attend the event, which marks the sovereign’s official birthday, are Queen Camilla and King Charles III, who is also receiving cancer treatment.

Charles made his return to public duties in April at an Easter church service. Buckingham Palace announced he was diagnosed with cancer in February after he underwent a procedure to treat an enlarged prostate.

Unlike last year’s Trooping the Colour, Charles will likely attend in a carriage rather than on horseback, the BBC reported.

The new photo of Kate Middleton came with a health update

In the photograph, which Sky News reported was taken earlier this week, Kate is seen posing next to a tree wearing jeans and a tan blazer with thin white stripes.

In the caption of the photograph, signed C, she shared a personal update about her condition. She said she’s making “good progress” with her chemotherapy and was starting to do some work from home, with the caveat: “There are good days and bad days.”

“My treatment is ongoing and will be for a few more months,” she wrote. “On the days I feel well enough, it is a joy to engage with school life, spend personal time on the things that give me energy and positivity.”

The royal event on Saturday marks Kate’s first official appearance since she said in a video released by Kensington Palace on March 22 that she was undergoing preventive chemotherapy.

Her diagnosis came after tests following a planned abdominal surgery in January found cancerous cells, she said in the video.

Her upcoming appearance marks her first since Christmas Day, when she was photographed taking part in the British royal family’s traditional walk to a church service in Sandringham.