Someone said (you, Henri?) that the duchess of Parma (I still think that's Irene!) wore a brooch from the Peacock parure. This set of jewels was given to Irene personally by her grandmother, n'est-ce pas? So it makes sense that the current duchess would wear a piece from this set.
I believe the v-H ladies wore some pieces from the Dutch royal collection, such as zut, forgot her name, who wore a dress borrowed from Maxima, and also wore the huge citrine brooch.
I was amazed to see Christina in a tiara. I don't know if I had ever seen her wear one before.