Kate Middleton attends Sunday service in Balmoral with royal family amid cancer treatment

Princess Kate was also joined by Prince William for the outing.

Kate Middleton was seen in a rare appearance Sunday as she attended service with the royal family amid her treatment for cancer.

The Princess of Wales was joined by her husband, Prince William, as the couple arrived at Crathie Kirk church on the Balmoral Estate on Sunday in photos obtained by the Daily Mail.

During the outing, Kate, 42, donned a light brown trench coat paired with earrings and a feather hat. Meanwhile, William was seen sporting a navy blue suit.

The photos show the couple apparently in high spirits, smiling and chatting while sitting in their vehicle.

Other royal family members who were also seen arriving for the Sunday service included King Charles III and wife Queen Camilla as well as Prince Edward and his wife, Sophie.

Kensington Palace hasn't commented on the photos.

Kate was most recently seen in public last month when she stepped out to attend the men's final at Wimbledon. She was seen sporting a purple Safiyaa dress and received a standing ovation from the crowd.

Prior to that, Kate made a public appearance in June at Trooping the Colour, where she wore a white Jenny Packham dress with black trim and a black bow.

At the time, Kate joined William and their children, Prince George, Princess Charlotte and Prince Louis, as well as other royal family members at the annual event.

Her appearance at Trooping the Colour also came after she shared a first update on her health since announcing her cancer diagnosis in March. She said at the time she was "making good progress" as she undergoes chemotherapy but was 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 June 14. "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 also said at the time her treatment would continue "for a few more months."

"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 added.