Pippa and Carole Middleton are set to rally around Princess Kate, following the royal’s cancer diagnosis. The Princess of Wales, 42, announced she is undergoing preventative chemotherapy following major abdominal surgery in January. Kate’s parents, Carole and Michael Middleton, along with her siblings Pippa and James, have been supporting the royal’s recovery at her cottage in Windsor, near their own homes. In a video statement released on Friday, Kate said: “In January, I underwent major abdominal surgery in London and at the time, it was thought that my condition was non-cancerous. “The surg…