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.”

Still, even this cautious return to normalcy will be a significant source of relief for the British royal family, which has struggled in recent months as both Catherine and Charles, her father-in-law, battled serious health problems.

Charles and Catherine are among the family’s most visible members. Their illnesses and sudden absence put a strain on the family, which was still coming to terms with the death of Queen Elizabeth II in September 2022.

Charles, who was hospitalized for treatment of his prostate in January, began to return to public duties in April. Last week, he took part in ceremonies to commemorate the 80th anniversary of the D-Day landings. He has looked healthy in recent appearances, though Buckingham Palace has released few details about his treatment or prognosis.

Charles marked his 75th birthday in November. But the formal birthday celebration, known as Trooping the Color, will be held on Saturday, as 1,400 officers of the Household Division parade before the king on a route that takes them from Buckingham Palace along the Mall to Horse Guards Parade, and back to the palace.

Catherine said she would take part in the parade, along with her husband, Prince William, and her three children, Prince George, Princess Charlotte, and Prince Louis. Palace officials said she would travel in a state carriage with her children and was expected to appear on the balcony of Buckingham Palace with the rest of the family. Rumors about her participation had circulated in Britain’s news media.

A spokesman for Buckingham Palace said that Charles “is delighted that the princess is able to attend tomorrow’s events, and is very much looking forward to all elements of the day.”

Kensington Palace, where Catherine and William have their offices, has not disclosed what type of cancer she has or her prognosis. The palace has pleaded for privacy while she undergoes treatment. After an initial cascade of rumors about her condition and whereabouts, she has been largely left alone by Britain’s tabloid newspapers.

Palace officials said Catherine had begun to work from home and said she would make decisions on attending future public events in consultation with her doctors.

In her statement, Catherine said her treatment would continue for a “few more months.” She spoke of the joy of engaging with her children about their schools and has become involved in some philanthropic work.

“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, as well as starting to do a little work from home,” she wrote.

“I have been blown away by all the kind messages of support and encouragement over the last couple of months,” Catherine added. “It really has made the world of difference to William and me and has helped us both through some of the harder times.”