What does she mean by "royal we"?

Native speaker’s answer
Rebecca
This is what we call the majestic plural! When sovereigns and royalty refer to themselves as the plural "we" instead of "I". The phrase "royal we" is mostly used as a joke. Ex: We, the queen, acknowledge your request. Ex: We're going out for dinner tonight! By "we", I mean just me. Ex: I told my wife, "we need to clean the house". She said, "Who? The royal we? I'm not cleaning today".