Princess Charlotte might only be 11, but one day, her father, Prince William , will become King. It’s a lot of responsibility for a tween to take on, but one matter that royal watchers have wondered about for years is which title Charlotte will be granted when she’s an adult. Speaking to Hello! magazine , royal biographer Robert Jobson shared two of the possibilities ahead for Prince William and Princess Kate’s only daughter. Traditionally, a monarch’s eldest daughter is given the title of the Princess Royal . In Queen Elizabeth’s case, her only daughter, Princess Anne , was granted the title. But the title is not hereditary, meaning it can’t be passed down to Anne’s daughter, Zara Tindall . Princess Anne will hold her title for life, but once she dies, it will return to the Crown. However, Jobson said that it’s not necessarily a given that Prince William will make Charlotte the Princess Royal.…