The Kardashians and Jenners have famously been trained by celebrities fitness expert Gunnar Peterson for many years. The family is sending their personal trainer “prayers” as he details his young daughter’s current battle with leukemia. Gunnar Peterson appears to be most closely linked to Kris Jenner’s daughter Khloé Kardashian. The mom of two has been on a transformational journey over the past few years and totally changed her looks. Gunnar appeared alongside Khloé on her reality TV show Revenge Body, given that he’s a fitness pro. Gunnar Peterson details daughter’s battleOn Wednesday, March…