I'm sure it enrages Meghan that Kate is wearing so many pieces that were associated with Diana, starting with the Cambridge Lover's Knot Tiara. All Meghan really got was the large and rather tacky aquamarine ring that Diana substituted for her engagement ring after the divorce. And it's really too big for Meghan as she is a much shorter and smaller-boned woman than Diana was.
There are rumours circulating that Meghan took off with some pieces of Diana's jewellery that she was only leant, not given, but don't quote me on that.
But along with so much else that bothered Meghan, Kate's access to major royal collection pieces must have really irked Meghan.
It doesn't seem to have occurred to Meghan that if she'd stayed on and made the remotest effort at recognising what the role of a constitutional monarchy was, and her place within it, she would have been loaned tiaras and suitable jewellery for state occasions, foreign royal weddings, etc., just as Sophie Wessex and Sarah Ferguson and the Duchesses and Kent and Gloucester were.
Instead, Meghan flounced out after less than 80 days of real work screaming about how victimised she was compared to Kate, who stayed the course, did the job she was really brought in to do, and after 7 or 8 years got to wear the family orders and sashes, increasingly splendid jewellery, etc.
Meghan's vision is so limited and short-term; it's her weakest characteristic.
Every attempt, from the Scobie to the Lacey book to the nasty stories Meghan and her PR and her friends leaked to the press has done absolutely nothing to damage the UK public's affection for the Cambridges. In the end, it all ricoscheted and made Scobie and Lacey and the Sussexes look bad.
And there's William on all the front pages with his Earthshot prize, his universally positively reviewed two-year documentary, and the Cambridges acting as Heads of State to the President of Ukraine and his wife.
The Sussexes and their handmaidens never seem to learn from their mistakes; it is regrettable to see a once-respected journalist-biographer like Robert Lacey (who, remember, also works for Netflix as a consultant on "The Crown") lower his standards to become one of those handmaidens.