According to the Independent, a bill is being introduced in Britain to put an end to the male primogeniture system. This would affect Prince William’s children, it’s said. Also note the past examples given at the end of the article.

bq. Almost 30 years after the passage of the Sex Discrimination Act, aimed to ensure equality between the sexes, an attempt is to be made to end the system of male primogeniture. Lord Dubs, a Labour peer and former minister, will today publish a Succession to the Crown Bill, which would also abolish the bar on the monarch or an heir to the throne marrying a Catholic and scrap the 1772 Royal Marriages Act, which requires the heir to get the monarch’s permission before marrying.