We don't know what is the source of NRC Handelsblad but they claim that the jewels can eventually be sold. My translation about the jewels:
"The jewels are placed in a foundation, but the heirs retain control. The board consists of the four daughters of Queen Juliana - Beatrix, Irene, Margriet and Christina. In an separate act Queen Juliana bequeathed each daughter one lot with valuables from the foundation. These lots are due now Queen Juliana is deceased. To prevent a fragmentation of the collection, there is a limitation. The daughters can not monetize their lot immediately. Their valuables must be offered to the other heirs first.
Part of the legacy thus appears divided in the Sixties. This also applies to the "roerende goederen" (movable properties) associated with the monarchy, like the regalia (crown, sceptre, orb) which were housed in 1968 in the Foundation Crown Properties of the House Orange-Nassau. Queen Beatrix is the sole director of the foundation. In the statutes Queen Juliana also arranged that proceeds of a sale of Crown Properties should befit all her daughters."
We don't know what happened between 2004 (decease of Queen Juliana) and today, but taking the statutes as starting point, the daughters can still sell jewels, artworks, inventories, archives and even the regalia... Also interesting is that Queen Juliana (according the article) has made a clausule in her testament stating that her heritage (that can not be the foundations since these are separate non-natural legal identities which can not die) can never become estranged by marriage. That means that any heir of Queen Juliana must separate her heritage from the mutual ownership in marriages. Queen Juliana had a considerable amount of personal jewels and these are subject tot that condition too.