Kate Middleton Says Prince Louis Is 'My Baby' but Admits He's 'a Proper Boy Now'

Kate Middleton can hardly believe that her youngest child is already a "proper boy."

The Duchess of Cambridge visited Little Village's hub in Brent, part of London's largest baby bank network, last month, where she was smitten by a baby resting in a stroller. The mother of three — Prince George, 9, Princess Charlotte, 7, and Prince Louis, 4 — made a remark about her own children growing up.

"I keep thinking Louis is my baby, but he's a proper boy now," Kate said of her son.

RELATED: Prince George Is Prince William's Twin — After Kate Said Louis Is the Only One Who Looks Like Her!

While Prince George and Princess Charlotte are quickly learning the royal ropes by joining their parents at family events and public engagements, Prince Louis is also getting to the age where he can participate in public life. In addition to already having his first public speaking appearance under his belt and mastering his royal wave, Prince Louis made a splash last month when he joined the royals at the Platinum Jubilee weekend celebrations, marking Queen Elizabeth's historic 70 years on the throne.

Louis joined his older siblings in making his Trooping the Colour carriage ride debut, waving enthusiastically to the crowds and even showing off his salute. When the family gathered on the Buckingham Palace balcony, Prince Louis adorably covered his ears as planes flew overhead.

Catherine, Duchess of Cambridge and Prince Louis of Cambridge
Catherine, Duchess of Cambridge and Prince Louis of Cambridge

Max Mumby/Indigo/Getty Kate Middleton and Prince Louis

The little prince also won hearts around the world at the Platinum Jubilee Pageant due to his enthusiastic waves, animated faces and interactions with his family.

"He's a cheeky monkey — a typical third child," someone who knows the family previously told PEOPLE. "It's nice that the world got to see him enjoying himself."

LONDON, ENGLAND - JUNE 05: Catherine, Duchess of Cambridge and Prince Louis of Cambridge watch the Platinum Jubilee Pageant from the Royal Box during the Platinum Jubilee Pageant on June 05, 2022 in London, England. The Platinum Jubilee of Elizabeth II is being celebrated from June 2 to June 5, 2022, in the UK and Commonwealth to mark the 70th anniversary of the accession of Queen Elizabeth II on 6 February 1952. (Photo by Chris Jackson/Getty Images)

Chris Jackson/Getty Kate Middleton and Prince Louis

Kate and Prince William, both 40, have previously hinted that their family is complete with three children. While interacting with royal fan Josh Macpalce during a 2020 visit to Bradford, the Duchess of Cambridge revealed that it is unlikely she will become a mom of four in the future.

"I don't think William wants any more," Kate said.

Kate also has several pieces of jewelry paying tribute to her three children by featuring their initials.

Prince Louis of Cambridge, Catherine, Duchess of Cambridge, Princess Charlotte of Cambridge, Prince George of Cambridge and Prince William, Duke of Cambridge
Prince Louis of Cambridge, Catherine, Duchess of Cambridge, Princess Charlotte of Cambridge, Prince George of Cambridge and Prince William, Duke of Cambridge

Chris Jackson/Getty Kate Middleton and Prince William with Prince Louis, Princess Charlotte and Prince George

But that doesn't mean Kate has grown immune to the charm of babies! Kate has admitted that she feels "broody" after meeting with young children.

"Can you get my wife out of here before she gets broody?" Prince William joked in May when the couple visited a Scottish class where students were learning about empathy by observing an infant — A.K.A. their "tiny teacher," Saul!

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On the first day of her solo royal tour in Denmark in February, Kate met with parents and their babies during a visit to the University of Copenhagen.

"It makes me very broody," Kate shared. "William always worries about me meeting under 1-year-olds. I come home saying, 'Let's have another one.' "