No, being a family member of someone important does not automatically make you important in your own right.
Ask Prince Edward of England.
Veressa is a notable character, but she is notable because she is Sylvanas' sister and the last two times she has been used in the story is because of who her sisters are. Notable is not important. Whatever role she had as the Alliance friendly Windrunner prior to the end of Legion has clearly been usurped by her far more interesting, far more important Void Elf sister.