I'd love to see Meghan in some of these jewels, but part of me feels that sapphires "belong" to Kate. She is most associated with them because of her engagement ring and the sapphire earrings she's already worn. So, part of me thinks that all the sapphires should go to Kate.
Instead, I'd like to see Meghan wearing other jewels - emeralds, pearls, diamonds. I don't know if she likes them, but I feel like she would look amazing in pearls - sophisticated and classy, and IMO they'd look gorgeous against her skin.
With regard to ownership of gifts, IMO it would depend on whether they were personal gifts (i.e. a wedding gift like Diana's sapphire set) or a gift bestowed during an official visit or tour. The latter would be gifts to the crown and therefore not belong to the recipient. But, the former - a wedding gift -that seems like it would belong to the recipient. I just don't see how the crown could take ownership of a personal gift. But, this is just my speculation, I could be completely wrong. (Although, one example supporting my case is Diana's engagement ring! That was a gift and remained her personal property.)