Prince Daemon Targaryen (Matt Smith), her uncle, brings scenes of brutality, arrogance, and a warrior’s mentality as commander of the City Watch in King’s Landing.
We also see the first female be named heir to the throne when King Viserys I chooses Rhaenyra to succeed him, achieving what Princess Rhaenys Targaryen (Eve Best), otherwise known as “The Queen Who Never Was,” did not.
Source: https://www.distractify.com/p/how-is-rhaenyra-related-to-daenerys