Charlotte and Louis are both sporting muddy knees in the new photo
William and Kate have previously spoken about their family's love of being outside. Back in February, the Duchess appeared on the
Happy Mum, Happy Baby podcast and when host
Giovanna Fletcher prompted the Duchess to complete the sentence, "I'm happy when…," Kate replied:
"I'm with my family outside in the countryside and we're all filthy dirty."
In the recent ITV documentary
Prince William: A Planet For Us All, the Duke also said of his eldest son George: "Seeing my children, seeing the passion in their eyes and the love for being outdoors… They find a bug or they love watching how bees are forming the honey.