The court has translated its interesting press release about the royal jewels, which offers some insight into the royal house's property arrangements, into English.
https://www.kongehuset.dk/en/news/crown-jewels-and-danish-royal-property-trust-jewellery
The Crown Jewels
[...]
By custom, the crown jewels remain in Denmark, which means that they are not carried along during visits abroad. The Danish crown jewels are the only ones in the world that are both exhibited as museum objects and, at the same time worn, by the country’s queen.
The history of the crown jewels goes back to Christian VI’s queen, Queen Sophie Magdalene, who, in her will from 1746, stipulated that her jewellery should not be passed to one specific person but should always be at the disposal of the country’s sitting queen, with the justification that “in this Royal House, there are so few jewels and no crown jewels at all".
[...]
The Jewellery in The Danish Royal Property Trust
[...]
The Danish Royal Property Trust was established by Frederik VIII and Queen Lovisa in 1910. The purpose was to collect and secure gold, silver and other valuable objects “which are desired to be kept in Our Family and therefore shall pass undivided from King to King of our House”.
The objects in a type of trust called a fideicommissum are passed down from generation to generation. They are not owned by the individual person, and a sale or pledging of the inheritance is therefore not possible.
[...]
Jewellery from The Danish Royal Property Trust is used by the sitting queen and can be taken abroad to be used at gala events.
[...]
The Royal House of Denmark’s private jewellery
The Queen and the other women in The Royal Family also have a collection of privately-owned jewellery that they have at their own disposal.
[...]
The original press release in Danish:
https://www.kongehuset.dk/nyheder/kronjuveler-og-fideikommissmykker
What would happen to the Crown Jewels according to Queen Sophie Magdalene's will of 1746 if there were no "sitting queen"? Does a female monarch (a legal though unlikely possibility as of 1746) qualify as a "sitting queen"?
It is interesting that the royal house still holds property constituted as an entail (fideicommissum), as some countries have abolished or restricted the use of entails. Is this arrangement allowable for private families?