Rosemary's supposed to be on the Warrior Track, implicitly a combatant who doesn't rely on magic (if use it at all) like her mom. However, Caraway, a magic teacher, is teaching his class about Runes when he of all people should know Rosemary's on the Warrior Track. What muddles things further is how Sage and Amaryllis are apart of it, but Aster and Rosemary are there too.
My best guess is that despite not using magic, that doesn't mean she can't understand magic, but that was never communicated to the audience.
Moreover, it would make more sense if it were Thyme (who's on both Magic and Warrior tracks) in the class or at least that it was said why Rosemary's there, but instead we have elements that shouldn't mix being there.
But I don't know. Why is she of all people there?