But when Prince George tried to join in, he was quickly silenced by Savannah, who put her hand over the third in line to the throne's mouth.
There's a comforting feeling when we spot a member of the royal family dressed in brands we normally shop-and nope, we're not talking about designer this time.
Immediately after the pictures of the family day out were made public, Twitter users rushed to share their opinions on the young Prince's toys, many shocked that George was so blatantly playing with them in public.
Kate also got in on the fun, as she had a go on Prince George's rainbow slinky and was also in fits of giggles as Charlotte attempted (and adorably failed) at her gymnastics.
Watch as Kate scoops up Princess Charlotte after she falls.
Prince Louis - who was born in April- was not there for the outing.
Little Charlotte adorably practiced her headstands in front of mother Kate, and was even sporting a pair of very cool sunglasses.
Prince George has previously been spotted wearing another style from the Hampton Canvas range at Trotters called the Nantucket.
Savannah is the Queen's eldest great-grandchild; she's the granddaughter of Princess Anne and the daughter of Peter and Autumn Phillips.
But photos immediately after show Kate was actually running to greet England polo player Malcolm Borwick, who appeared to be beckoning her from beside the white marquees a few metres from the grass bank.