It would be interesting to see if we could track down photos of her wearing all those tiaras.
The only image I have of her wearing one of her smaller tiaras is from 1931.
Most photos seem to show her wearing the one with the Sancy diamond. Lady Astor wore it for all major occasions. Below is a photo from the 1937 Coronation.

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Reading the memoirs of Lady A's
personal maid Rose is fascinating...Lady A actually had 5 tiara's