There are several synonyms for the phrase "Her Royal Highness" which is typically used to refer to a female member of a royal family. Some common alternatives include "Princess," "Queen," "Regent," "Empress," and "Duchess." Each of these terms denote a woman who holds a high level of power or authority within a monarchy, and they may also be used to distinguish different levels of status within a royal family. Depending on the context and location, the exact title and accompanying privileges associated with each of these synonyms may vary. Nonetheless, they are all indicative of a woman of noble birth and high social standing.