At one side I understand Mrs F. van België/de Belgique/von Belgien née De Mora y Aragón being unwilling to share her jewels with her sister-in-law Mrs P. van België/de Belgique/von Belgien née Ruffo di Calabria.
At the other side I don't understand Queen Fabiola of Belgium being unwilling to share her jewels with her sister-in-law Queen Paola of the Belgians.
The first sentence is about the private person, the second about the public person, the Première Dames of Belgium. I would expect that for the sake of the monarchy, for the House, for the dignity of the throne which her revered late husband once reigned for 40 years, that Fabiola would enable Paola to go out with all possible parafernalia which are attached to her high position and status. For sure since Queen Fabiola herself never wears grand jewels anymore.