The earliest photos I have of QEQM wearing parts of this brooch are from February 1937, so well before the coronation. It might be that the jewel was an accession gift, or that someone gave her a grand Christmas present in 1936. The jewel may have also been languishing in the royal vaults for some time. In the early photos of QEQM after she became Queen we got to see a number of jewels previously unseen. For example, a snake bracelet said to have belonged to Queen Alexandra. It is all intriguing!