A coronation was different from being crowned as the queen of the lycanthropes. A coronation meant people would recognize you as the luna of the pack. In this kingdom, only when you married the king would you become the queen.
While being the queen could give you absolute power just like the king, being a luna meant you could only have the same power. However, the king was still above you. Being the luna instead of being the queen, the only difference was that you would have less power than the latter.
But basically, it was the same thing.
This coronation would let the people knew about Hazel ceremoniously, so it would be more proper to introduce her.
Needless to say, this was a big day for Hazel and nervous was an understatement to describe how she felt right now.