Kate Middleton shares health update along with new family photos

Kate, the Princess of Wales, is opening up about her health six months after announcing she had been diagnosed with cancer.

Kate, the wife of Prince William and a mom of three, said in a video message Monday that she is focused on staying "cancer free" and gradually returning to work after completing chemotherapy.

"As the summer comes to an end, I cannot tell you what a relief it is to have finally completed my chemotherapy treatment," Kate, 42, said in the video message shared by Kensington Palace. "The last nine months have been incredibly tough for us as a family. Life as you know it can change in an instant and we have had to find a way to navigate the stormy waters and road unknown."

Kate went onto describe her cancer journey as "complex, scary and unpredictable for everyone," adding of the perspective it's given her, "This time has above all reminded William and me to reflect and be grateful for the simple yet important things in life, which so many of us often take for granted. Of simply loving and being loved."

The video gives an intimate glimpse into Kate and her family, including William and their three children, Princes George and Louis and Princess Charlotte.

The footage, taken by photographer Will Warr in August in Norfolk, England, shows the Wales family playing outside, enjoying a picnic together and embracing in hugs and kisses.

In one clip, Kate, William and their three children are seen playing a card game with Kate's parents, Michael and Carole Middleton.

In other clips, William and Kate are seen holding hands and embracing.

Kate announced in March that she had been diagnosed with cancer after undergoing what the palace described as "planned abdominal surgery" in January.

She has not revealed publicly what type of cancer she faced, nor exact details of her treatment beyond that she was undergoing "preventative chemotherapy."

In the newly-released video, Kate said she plans to take on a few additional public duties after remaining out of the public spotlight for most of the past year.

"Doing what I can to stay cancer free is now my focus. Although I have finished chemotherapy, my path to healing and full recovery is long and I must continue to take each day as it comes," she said. "I am however looking forward to being back at work and undertaking a few more public engagements in the coming months when I can."

Since March, she has been seen only a few times publicly, including attending Trooping the Colour in June and watching the men's singles final at Wimbledon in July alongside her daughter Charlotte.

Prior to attending Trooping the Colour in June, Kate shared a health update, saying she was "making good progress" while undergoing chemotherapy but was not "out of the woods yet."

Kate said at the time that her treatment would continue "for a few more months."

Kate's absence from public duties came at the same time that her father-in-law, King Charles III, also faced a cancer diagnosis.

Buckingham Palace announced in February that Charles was diagnosed with cancer, but did not specify the type of cancer, the stage of cancer or the type of treatment.

Charles also spent time away from public duties before returning to a modified schedule of public engagements in late April.

The king's first public royal engagement since his own cancer diagnosis was a visit to a cancer treatment center in London.

In response to Kate's announcement that she had finished chemotherapy, a Buckingham Palace spokesman told ABC News in a statement that Charles and Camilla, "consider the details in today's announcement to be wonderful news and will continue to offer all love, thoughts and support to The Princess on her continued path to full recovery."