Kate Middleton hasn’t been seen in public in the last few months as she battles cancer, but according to an anonymous friend, her treatment has “turned a corner.” “It has been a great relief that she is tolerating the medication and is actually doing a lot better,” the pal told an outlet. In March, the mom-of-three took to Instagram to update the world on her health after months of “Where is Kate?” theories spread on social media. “I wanted to take this opportunity to say thank you personally for all the wonderful messages of support and understanding whilst I’ve been recovering from surgery,”…