While Savannah got a swift telling off from her mum, Autumn, the future King turned to his mum for comfort, and Kate was snapped consoling the little Prince and stroking his cheek.
In April, she charmed fans when she accompanied her father and brother to the Lindo Wing to meet Prince Louis for the first time and began waving as soon as she stepped out of the family vehicle.
All eyes were on Prince George and Princess Charlotte on Sunday as they frolicked in the sunshine at their father's polo match.
But while many criticized the fact that the little prince was allowed to play with a plastic gun, the debate has been ongoing as others have risen to the defense of children playing with such toys.More news: Australia says end to South Korea-US war games not a certainty
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Another said: 'This isn't okay anymore... My American side here, biased maybe b/c of everyday #gunviolence in U.S., but my British side agrees.
The children entertained themselves with toys and ran around in the sunshine - and the pictures of the fun family day out are too sweet.
"Completely tone deaf of Kate... to give Prince George a toy gun. Lucky George isn't black or police would have shot him", one user wrote.
What do you think about the toy gun?
The royals' casual outing came just one day after they played a formal role at Trooping the Colour, the official celebration of Queen Elizabeth's 92nd birthday. Join the conversation over on our Facebook page and let us know your thoughts!