Kate Middleton’s mother, Carole, is remaining by her daughter’s side and being an unwavering support as the Princess of Wales bravely undergoes treatment amid her cancer battle. The royal family has rallied together amid news of her health discovered in the wake of abdominal surgery done earlier this year in January. The future queen of England said doctors were of the belief that her condition was not cancerous, but tests completed after the procedure found that “cancer had been present,” RadarOnline.com has learned. “My medical team therefore advised that I should undergo a course of prevent…