London/IBNS: Catherine, Princess of Wales, Thursday shared a glimpse of her daughter Princess Charlotte on her ninth birthday, the second such photograph of her children in as many weeks, as she stays out of the public eye while battling cancer.

The 42-year-old future queen was credited with having taken the photograph shared on royal social media platforms.

On April 23, she was also said to have been behind the camera for a click of her younger son Prince Louis on his sixth birthday.

Charlotte is currently third in line to the throne behind her elder brother Prince George, 10, and their father, Prince William, 41.

Both photographs follow a row in March over a Mother's Day post by Catherine featuring herself with her three children which she later admitted to have digitally altered.

The British royal family has been hit by the enforced withdrawal from the public life of Kate, and her father-in-law King Charles III due to cancer treatment.

Neither the king's Buckingham Palace office nor William and Kate's at Kensington Palace have disclosed what type of cancer each royal has.