Celebrity Kate Middleton Reveals That Princess Charlotte Is "Cute but Feisty" By Jennifer Davis Jennifer Davis Twitter Jennifer Davis is a writer, editor, and content strategist living in Atlanta. She was previously the Associate Editor for InStyle, and is currently working as a Digital Content Manager at Cox Business. InStyle's editorial guidelines Updated on June 10, 2016 @ 03:15PM Pin Share Tweet Email Photo: Handout Sounds like the Duke and Duchess of Cambridge have their hands full! While at the Queen's 90th birthday celebrations in London, Kate Middleton opened up about her one-year-old daughter, Princess Charlotte, and it seems that despite her sweet demeanor, she's a bit of a wild child. "Oh, she is very cute but she has got quite a feisty side!" Kate told attendee Glynis Double, according to People. She went on to say that she hopes older brother Prince George can keep his little sister in line. As we've seen the three-year-old royal's "naughty" ways (who can forget when he stuck his tongue out at last year's the Trooping of the Colour parade), we have a feeling that he'll be recruiting her for mischief instead of helping her stay out of trouble. The royals were all on hand on Friday to celebrate Queen Elizabeth's milestone birthday. Along with her husband, Prince William, and brother-in-law, Prince Harry, Kate attended a service at St. Paul's in a ladylike Catherine Walker coat dress, which featured delicate embroidery. She topped off the look with an eye-catching fascinator. VIDEO: See Kate Middleton's Most Memorable Outfits This was the second blue ensemble that Kate wore this week. Yesterday, she stepped out in a vibrant cobalt Roland Mouret gown that featured a fashion-forward cut-out shoulder for the SportsAid dinner.