"They are awesome!" To finish off the day, the royal mom - who looked lovely in Zara jeans, Penelope Chilvers boots and a green Fjallraven coat - shook hands and hugged each child goodbye. So she does have something in common with the average mum, after all.
This royal outing was the flawless way to start back up on her royal engagements.
"Look, I made this", one child told Kate.
The Duchess of Cambridge is back, and looking fab!
In 2004, Kate was spotted wearing the same boots while modelling for the United Kingdom clothing brand "Really Wild Clothing" during the Game Fair event at Blenheim Palace.
Both William and Kate, along with Prince Harry, started Heads Together in 2016, and all three have shown a passion for a particular area of mental health, with William often speaking out on men's issues.
And on October 12, she will join the rest of the royal family as they celebrate the wedding of Princess Eugenie to her fiance Jack Brooksbank, at Windsor Castle's St George's Chapel.
She also attended the Trooping the Colour celebrations to mark the birthday of Queen Elizabeth in June, and attended the Wimbledon tennis tournament with Meghan, albeit in a private capacity, in July.
During Tuesday's event, Kate got down in the grass with a young student as they hunted for "mini beasts", but they could only find slugs.