See brooch worn by QEQM between time = 0:30 and 1:01 on YouTube video below



Is the provenance of this very large brooch known? In my search for information i found this list of Pss Margaret's jewels posted by Frank in 2020.
https://mb.boardhost.com/historyroyaljewels/msg/1603131483.html
Is this the brooch listed as:
IV. Jewels not sold and not seen since Princess Margaret's death
e. The huge diamond floral spray brooch from Queen Elizabeth the Queen Mother (Maybe from the Greville’s bequest) ?