Mm, Luna Nova's an all-girls school. Doesn't mean it can't have visitors. Wizards are rarer in our world, magic mostly appears in women. But really, it's mostly just a school like any other. We just gear toward refining the ability to use magic. Like, a girl may be fantastic at flying a broom, or culinary magic, but wasn't really taught much about numerology or even star-reading.

[ So basically it covers what a girl might not learn at home and give her the necessary broad knowledge base for being a witch. ]