I don't think this is going to happen anytime soon, Adelaide.
The ladies of the SRF will continue to use discreet pieces of jewellery simply because they are under the "watchful eye" of the Republican Spaniards, who would never happy seeing the ladies wearing sumptuous jewels.
I think the SRF is very smart and they don't want to give these people any reason to believe that they have an extremely lavish lifestyle by wearing exorbitant jewels.
Just look at the Queen. Even when she wears grand tiaras such as the Cartier or the fleur-de-lys, she will wear simple -yet tasteful- necklaces. I think this is a smart move or the Republicans would be shocked! the royals know that the monarchy in Spain is a fragile institution, so they act accordingly!
To be honest I believe that these ladies must have impressive jewels in their vaults, especially the Queen, who must have got some nice pieces from the Arab royals, who are very good friends of her husband.