London, May 6 -- As Princess Charlotte, the only daughter of Prince William and Princess Catherine, turned 10 on May two, she quietly marked a milestone not only in age but her evolving role within the British royal family. Born in 2025, Charlotte became the first female royal not to be displayed in the line of succession by a younger brother, a historic shift enabled by the Succession to the Crown Act 2013. Guided by parents' intent on balancing tradition with modernity, Charlotte is being raised in a household that merges royal responsibilities with ordinary childhood experiences. "Kate has the reins of power in a very subtle way. She has very strong views," royal author Ingrid Seward tells PEOPLE. Noting that the Princess of Wales' de...