If William, Kate Have Daughter, She'll Be 'Princess' Queen announces rule change By Evann Gastaldo, Newser Staff Posted Jan 10, 2013 10:30 AM CST 9 comments Comments Britain's Prince William stands next to his wife Kate, Duchess of Cambridge as she leaves the King Edward VII hospital in central London, Thursday, Dec. 6, 2012. (AP Photo/Alastair Grant) (Newser) – Ever-so-important news: Prince William's forthcoming progeny with wife Kate, the Duchess Formerly Known as Middleton, will be a princess if it is indeed a girl. Queen Elizabeth made the announcement yesterday, People reports. For the past century, the somewhat confusing rule would have meant that William's daughter would have had the title "lady." The rule change comes after another change last year that allows a firstborn daughter to ascend the throne. The official announcement notes that this most recent change will apply to all of William's offspring: "All the children of the eldest son of the Prince of Wales should have and enjoy the style, title, and attribute of royal highness with the titular dignity of Prince or Princess prefixed to their Christian names or with such other titles of honor."