When the right time comes, Princess Charlotte will likely be known as the Princess Royal, the current title of Princess Anne, Queen Elizabeth's one and only daughter. Princess Anne's daughter, Zara Tindall, is not going to inherit this title from her mother. 

Princess Anne was named the Princess Royal in 1987, when she was already married and a mother. The title was previously held by Princess Mary, the Queen's aunt and the sister of King George VII, from 1932 to 1965. 

According to reports, the said title is only given to the eldest daughter of the monarch. As Prince William, Princess Charlotte's father, is the second in line to throne, it is assumed that he will become the monarch one day as well, after his father, Prince Charles, the heir to the throne.

Princess Anne is the 14th in the line of succession and will have little chance of becoming a monarch. Thus, Zara will never become the daughter of a monarch. 

However, the title of Princess Royal is still not guaranteed to Princess Charlotte because bestowing this is upon the monarch's discretion. Only one can carry the title at a time and it can be inherited upon the death of the current Princess Royal. It actually took some time for Princess Anne to inherit the title from her great aunt because Queen Elizabeth didn't hand this down immediately upon Princess Mary's death.

In the past, the title of Princess Royal had a special responsibility based on the Magna Carta. Apparently, a man caught sleeping with the Princess Royal can be tried for High Treason and the punishment is death. The law, however, was changed in 1998.

At any rate, Princess Charlotte will prove to be a worthy successor of the royal title. Princess Anne, as the Princess Royal, stood for being no-nonsense and was one of the hardest working members of the royal family.

Some say that Princess Charlotte has the same fierce streak as Princess Anne and her personality is already shining through at five years old. Princess Charlotte is quite outspoken, confident and strong-willed for a little girl. 

Prince William and Kate are actually getting praises for the way they've raised their daughter as she is showing immense leadership qualities, just like Princess Anne. The Cambridges have always said that they are trying to raise all three kids in a normal environment as much as possible, with a lot of nurturing and care.