Kensington Palace has issued thank you cards to kind-hearted members of the public who sent their well wishes to Kate Middleton as she undergoes chemotherapy.The Princess of Wales, 42, revealed in a heartfelt video message at the end of March that she is in the early stages of treatment following a cancer diagnosis. In the video, the future Queen described the past few months as 'incredibly tough' for her family but reassured everyone that she was 'well and getting stronger every day'.