Charlotte is wearing trousers, a knapsack that is snugly fastened on her back, and a £37 Jack Pyke children’s “Evolution Camo” jacket.

Instead of the more formal pigtails we frequently see her wearing, her hair, which is quite similar to Kate’s, is pulled back in a loose ponytail and oddly disheveled by the wind.

She is giggling, grinning widely at her mother, and seems incredibly content and carefree.

Charlotte was mostly at home in earlier birthday photos, dressed more formally in skirts and jumpers.

Over the years, and especially in the past several months, Kate has talked extensively on the value of spending time outside with her family.

She has discussed how the natural world has provided her with a great deal of comfort during her cancer battle and how it has contributed to her healing