Pippa Middleton is “carrying out James Middleton’s promise to Princess Kate”, a royal commentator exclusively told GB News. In March, Kate announced she had begun a course of preventative chemotherapy following a diagnosis of cancer. She subsequently stepped back from public life and was not seen again until her appearance at Trooping the Colour in June. James Middleton, Kate’s younger brother, took to Instagram with a personal message and tribute to the Princess of Wales after she announced her cancer diagnosis in March. Posting a throwback photograph of the pair as children, James wrote: “Ov…