Article continues below advertisementPrincess Charlotte has emerged as a source of strength for her mother, Kate Middleton, during one of the most challenging periods of her life, OK! can reveal.Sources reveal the 10-year-old royal has been quietly supporting Kate through cancer treatment, offering both comfort and cheer while balancing her own public and sporting engagements.Charlotte, the second child of Prince William and Kate, both 43, has long captivated the public since her birth on May 2, 2015.