—with many insisting she is the double of in the photograph.The Earl shared the image on his Instagram page this week, writing, "My first day of school, in September 1968: my father took this photograph of me and my sister, Diana, just before he drove us to Silfield, a really lovely primary school in King’s Lynn, Norfolk. The headmistress was Miss Jean Lowe, a warm and thoughtful lady who loved her boys and girls…I was there till 1972, when I headed off to the place I call—in my memoir—A Very Private School."In the photograph, Diana can be seen standing next to Charles, the two dressed in matching red blazers, red ties and long gray socks.