The Cambridge children were able to ask questions of the veteran TV broadcaster, who they are big fans of.
Kate made the comments while speaking to families involved in BBC project, Tiny Happy People.
The young royal has drawn comparisons with his own siblings as well as his grandparents and his uncle.
Charles has shared a picture of him hugging one of his youngest grandchildren to mark the birthday.
The Duchess of Cambridge captured what happened in reality when she took her son's birthday photos.
The couple released further details, some of which were "saddening."
The Cambridge children hadn't met their baby cousin until that moment, according to one royal expert.
The Duke and Duchess of Cambridge’s three children met baby Archie for the first time when William and Harry played at the King Power Royal Charity Polo Day, it has been revealed. The Sun’s royal correspondent Emily Andrews tells Yahoo UK’s ‘The Royal Box:' "It was interesting actually that polo match because it was the first time that Charlotte and George had actually met Archie, they hadn’t actually met him for two months, so that polo match was lovely." Prince George, then five, Princess Charlotte, four, and one-year-old Prince Louis were spotted playing together on the sidelines, as Kate and Meghan, holding their two-month-old cousin, stood side by side.
“You go back a couple of generations and it was literally like waxworks coming out, it was very stiff and there wasn’t much hands-on parenting at all.”