Kate Middleton appears to have swapped her blue engagement ring, which once belonged to Princess Diana, for a new ‘eternity band’.The stunning new piece of jewellery was on show in a moving new video released by the Royal Family, in which Kate revealed that her treatment for cancer has come to an end. In a voiceover, Princess Kate, 42, says: “As the summer comes to an end, I cannot tell you what a relief it is to have finally completed my chemotherapy treatment.” She can be seen enjoying the outdoors, strolling through fields and spending time together in the countryside with husband Prince William and their three children, Prince George, Princess Charlotte and Prince Louis.