This lovely Diamond brooch seen worn by the late Queen for her visit to Somerset in 2019 is known to many (including me) as the Jardine brooch. However, I came a cross an interesting post on Ursula's site Royal Magazine:

https://royal-magazin.de/england/queen-elizabeth/queen-elizabeth-diamond-stars-16th-birthday-king-queen-england.htm

In this piece it says that although it has been said and repeated many times that this brooch was a gift from one Lady Jardine it might actually be a piece with a much more sentimental value to the late Queen. It claims that it might be one of two pieces that Queen Elizabeth the Queen Mother owned and that she had been wearing them as headpieces at certain events. The brooch was then given to Her late Majesty on her 16th birthday.

This is news to me and I just stumbled upon the information by chance. Is this something that others have known for a while already?

In a way it makes sense as the Queen seemed to favour this brooch above many of her other brooches in her collection. And since the Princess Royal also has a similar brooch in her collection it could actually be the second of this pair of star brooches owned by Queen Elizabeth the Queen Mother.