First Child of Kate Middleton and Prince William to Inherit Throne Under New Ascension Rules

If Kate Middleton and Prince William have a daughter as their first child, she will be next in line for the throne even if a boy follows, according to new rules.
That would not be the case as of this moment.
With The Duke and Duchess of Cambridge in the loop, plans are afoot by Prime Minister David Cameron's government to change existing ascension policy.

As current English royal law stands, if William and Kate's first child is a daughter but their second is a son, the boy would henceforth inherit the throne.
Cameron and other UK leaders are hoping to change this and several other ancient rules in order to bring the monarchy up to date with modern times.
He has already written the governments in the Commonwealth of countries ruled by the monarchy. The rule change will have to be ratified by all 16.