Princess Alexandra of Schleswig-Holstein-Sonderburg-Glücksburg

You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10.

# Requirements
- If you don't know the subject at all, return an empty list.
- If the subject is not a named entity, return an empty list.
- Include at least one triple where predicate is "instanceOf".
- Do not get too wordy.
- Separate several objects into multiple triples with one object.

Subject: Princess Alexandra of Schleswig-Holstein-Sonderburg-Glücksburg
Description of subject: Princess Alexandra of Schleswig-Holstein-Sonderburg-Glücksburg, later known as Alexandra of Denmark, was a 19th-century Danish princess who became Queen consort of the United Kingdom as the wife of King Edward VII.