With the birth of her little brother, Princess Charlotte became the first royal girl in the British monarchy to not have her position in the line of succession to the crown usurped by a younger brother.
Traditionally, the line of succession followed the males born to the family, and if there were no males, it would fall to the oldest female. This is known as male-preference primogeniture.
The Succession to the Crown Act 2013 changed all of this. First implemented in 2015, the new Act of Parliament changed the line of succession from male-preference primogeniture to absolute primogeniture.
Absolute primogeniture throws out the male focus of succession and instead falls to the eldest child regardless of the gender.
Throughout the history of the British royal family, a female child was always usurped by a younger male sibling, but Princess Charlotte will be the first to keep her spot in the line of succession.
She will hold her spot until her older brother, Prince George, has a child meaning she has a couple of decades before she starts to fall down the line.
In related news, read the full details of the new royal baby in the next article below!