The royal siblings helped their mom gather moss, leaves and twigs for the RHS Back to Nature Garden.
The royal siblings couldn't have looked cuter in just-released images from their visit to the RHS Back to Nature Garden, which was designed by their mother, Kate Middleton, alongside award-winning landscape architects Andrée Davies and Adam White of Davies White Landscape Architects.
George, Charlotte and their little brother, Prince Louis, helped their mom with the project, as they gathered moss, leaves and twigs to help decorate the RHS Back to Nature Garden. Hazel sticks collected by the family were also used to make the garden's den.
Photos from Sunday's event show Charlotte recreating her mom's pose on a rope swing and dipping her toes into a stream with George. Prince William is seen in the background holding onto Louis as the 1-year-old explores the garden from the other side of the bridge.
Other photos shared to Kensington Royal's Instagram show Louis walking and the family having fun in the garden.
The Duchess of Cambridge couldn't be more proud of her latest project.
"In recent years, I have focused much of my work on the early years, and how instrumental they are for outcomes later in life," she said an Instagram caption accompanying a photo of her in the garden. "I believe that spending time outdoors when we are young can play a role in laying the foundations for children to become happy, healthy adults."
Sunday also marks the 1-year anniversary of Prince Harry's wedding to Meghan Markle. See more in the video below.