Queen Elizabeth delivers her Christmas speech annually, and is generally wearing one or more pieces from her personal jewellery collection. These are items that were (usually) handed down from aristocratic relatives; the Duchess of Cambridge pearl pendant brooch was owned first by Princess Augusta. Queen Elizabeth inherited it in 1953. It can be seen on pg. 133 of The Queen’s Jewels by Leslie Field, where there are photos of it being worn by Augusta; Queen Mary; and Queen Elizabeth.