Kate, 42, the wife of Prince William, said Friday that she is "making good progress" as she undergoes chemotherapy but is not "out of the woods yet."
"I am making good progress, but as anyone going through chemotherapy will know, there are good days and bad days," Kate said in a written message shared by Kensington Palace. "On those bad days you feel weak, tired and you have to give in to your body resting. But on the good days, when you feel stronger, you want to make the most of feeling well."
Kate said her treatment will continue "for a few more months," adding, "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."
SEE ALSO: Kate Middleton says she was diagnosed with cancer, is undergoing chemotherapy
Kate Middleton diagnosed with cancer, undergoing chemotherapy
Kate also confirmed in her message that she will join members of the royal family on Saturday for Trooping the Colour, the military parade held annually to mark the reigning monarch's official birthday.
"I'm looking forward to attending The King's Birthday Parade this weekend with my family and hope to join a few public engagements over the summer, but equally knowing I am not out of the woods yet," she said. "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."
Kate also described herself as having been "blown away" by the support she has received since publicly revealing her diagnosis.
"It really has made the world of difference to William and me and has helped us both through some of the harder times," she said, adding at the end of her message, "Thank you so much for your continued understanding, and to all of you who have so bravely shared your stories with me."
In addition to the health update, the palace on Friday shared a new photo of Kate, taken this week in Windsor, England.
Kate's appearance at Trooping the Colour will be the first time she has been seen publicly with the royal family since December, when she attended a Christmas Day service in Sandringham.
Just weeks after Christmas, in mid-January, Kate was hospitalized for what the palace described at the time as a "planned abdominal surgery."
After a nearly two-week hospital stay following the surgery, Kate continued to take time off from royal public duties in order to recover.
In March, amid growing speculation about her health and absence from the public eye, Kate announced in a pre-recorded video message that she had been diagnosed with cancer.
Speaking alone and directly to a camera, Kate described the cancer diagnosis as a "huge shock" for her and her family. She said the cancer was discovered in post-operative tests after her abdominal surgery in January.
The type of cancer has not been disclosed. According to the palace, Kate started a course of preventative chemotherapy in late February.
While Kate has remained out of the public eye during her treatment, William returned to work in mid-April. Over the course of his royal engagements, William has shared few updates on Kate, but thanked fans for their support, replying "yes" to a person at an event earlier in June, who asked if Kate was "getting better."
William and the couple's three young children, Princes George and Louis and Princess Charlotte, will join Kate at Trooping the Colour on Saturday. The family is expected to take part in the parade and stand on the balcony of Buckingham Palace, per tradition, to watch the military flyover.
This year's celebration will mark the second Trooping the Colour of King Charles III's reign.
Charles, 75, was also diagnosed with cancer earlier this year, but has since returned to public duties.
Like Kate, Charles will also take part in this year's Trooping the Colour. He will take on a slightly modified role by riding in the parade in a horse-drawn carriage alongside his wife Queen Camilla instead of on horseback, according to Buckingham Palace.
Charles' cancer was announced publicly in February. The palace has not shared what type of cancer he was diagnosed with or what type of treatment he is undergoing.