Kate Middleton has indeed worn several pieces that once belonged to Princess Diana. Most famously, she wears Diana’s sapphire-and-diamond engagement ring, which William used to propose in 2010. Harry has clarified that William inherited the ring after their mother’s death, contrary to earlier reports that it had been in Harry’s possession.
Kate has also worn other Diana heirlooms, including a three-strand pearl bracelet designed by Nigel Milne in 1988. The bracelet was inherited by William after Diana’s death in 1997 and later given to his wife.