The Duke and Duchess of Cambridge use modern parenting techniques to help their three children feel 'valued, listened to and secure' in their most recent family video, parenting experts have claimed. Kate Middleton, 39, and Prince William, 38, posted a short clip to the Kensington Royal Instagram page showing themselves enjoying the great outdoors as they thanked supporters for sending 'kind messages' on their tenth wedding anniversary. Joined by their three children - Prince George, seven, Princess Charlotte, five, and Prince Louis, three - the clip gives an unprecedented glimpse into their family life. They are seen embracing the company of their children in co-ordinated casual wear as they climb the sand dunes on the beach in Norfolk, sit around the campfire toasting marshmallows in the countryside and play in the garden of their Anmer Hall residence.