We need to remember that there are plenty of royals in Europe who have no worries for life but nevertheless make (or made) a career. But... if these royals wanted to have a private life somewhere on an estate and dedicate himself to that estate, that would have been perfect as well.
An example is Prince Gustav zu Sayn-Wittgenstein-Berleburg, the son of Prince Richard and Princess Benedikte (née Princess of Denmark). He manages the enormous family assets. But when you ask: "What is his occupation?" Then eeeeerrrrhhhh... he has none, he manages the family estate. So it is not easy to stick a label on it, it is often not a job, it is part of their life.
Look at Downton Abbey (in reality Highclere Castle) and look at the Earl of Grantham (in reality the Earl of Carnarvon). In both the series as well in real life the Earl has no regular job. Nevertheless he is a very busy man, whom has more things to do than he has time for...
Princess Beatrice should marry someone like Lord George Percy, Earl Percy
, the son of the Duke of Northumberland. Then she can be very busy as the (future) lady of Alnwick Castle
. Problem solved.