These are particularly tricky questions.
When talking about a King or Princess we refer to them as "Princess Diana" or "King Edward".
Any other fields that they are interested in do not come into their title. This means we would usually say:
- the King who is a scientist or the King who is interested in science
- the King who is a developer or the King who is interested in development
- The Princess who is a lawyer
I hope this helps.

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