A legal scuffle in the British Commonwealth is putting a hold on a new law to ensure that a female heir to throne can't be overtaken by a younger brother. Originally, Queen Elizabeth II only ascended to the throne because she had no brothers.
Prince William and Kate Middleton are currently expecting their first child this month, who is third in line to take the throne behind Elizabeth's son Prince Charles and her grandson, William. If William and Kate have a girl, she can be queen, and cannot be succeeded by any younger brothers. If the new law isn't legislated unanimously across Queen Elizabeth's kingdom, and if William and Kate's second child is a boy, he could supersede a firstborn girl.