I think given her position, Kate really does not have access to that much fancy jewelry. She wears the Cambridge lover's drop tiara and sometimes the lotus flower.
I have started seeing her in a few pieces of the QM.
William has bought her some nice pieces; as have her parents, and she has worn some of Diana's jewellery, usually reworked earrings.
Diana herself didn't have that much jewelry; it seemed like more as she always wore a tiara, like most people pop on a hat, but it was only her own Spencer tiara or the Cambridge lover's knot. She also famously wore a lot of costume jewellery from Butler and Wilson.
I would love to know what has happened to her Aquamarines. Perhaps, as well as the ring, we will slowly see them appearing on meghan.
Camilla has the most fantastic bling; She wears all of the QM jewellry, The Delhi Durbar and the Greville tiara. Ropes of diamonds and she has been gifted lots of jewels from the ME. I think Prince Charles buys her a lot.
Poor old sophie has very little in the way of impressive jewellery. Her Wedding tiara was not the prettiest. I hope when she becomes Duchess of Edinburgh, they crack open the jewellry vaults for her.
I'm sure we haven't seen the full extent of Queen Mary's jewellery being worn,