Catherine, the Princess of Wales, said on Friday that she planned to take part in a parade on Saturday marking the birthday of King Charles III, a tentative return to the public stage after confirming in March that she was being treated for cancer.

The news, which Catherine released in a highly personal six-paragraph statement, reflected both the progress she has made since she was first hospitalized for abdominal surgery last January and the long road to recovery she still faces.

“I am making good progress, but as anyone going through chemotherapy will know, there are good days and bad days,” Catherine wrote.

“On those bad days you feel weak, tired and you have to give in to your body resting,” the princess said. “But on the good days, when you feel stronger, you want to make the most of feeling well.”

Catherine, 42, said that she hoped to take part in a few other public engagements during the summer. But the princess, who has not been seen in public since last Christmas Day, emphasized that her appearance in the parade on Saturday — her first in several months — did not represent a formal return to public life.

“I am not out of the woods yet,” she wrote. “I am learning how to be patient, especially with uncertainty. Taking each day as it comes, listening to my body, and allowing myself to take this much needed time to heal.”