Basically, a hunter was fighting a daemon and, knowing that they could not defeat it, sealed it inside of her. So she's been existing for about 10 years now with a dormant daemon inside, and while she's technically considered a contracted, she's also extremely atypical. It's assumed by the faculty that one day that daemon will get out, and she's at the Academy both to hone her powers, and to keep her in check.

So yeah. It's a really shitty situation tbh. But she's just so darn chipper that you would never know it.