"What kind of monster attacked you?" The question is innocent enough, like she's trying to make plans about how to defend yourself. The way she holds herself is different than what you'd expect. In the few street fights you've seen and been in, the small knife was between the two, but she holds her empty arm forward, and her knife armed hand back, clenched against her side. It sort of clicks how that would be a much more viable style, her empty hand a defensive weapon, her other hand back and cocked.
She does make a sharp gesture with her empty hand, and a floating misty knife materializes before you. You aren't sure, but it seems like the 'blade' isn't dangerous, like the spell is there, but not will break apart if anything substantial hits it. Ideal for training.
Spoiler (click to show/hide):
I meant her personality. Also, did you have a preferred style of magic system? I was thinking of making it a planned style, perhaps with a magic book where you write down the spellforms and then you can summon the spell, and it burns itself out of the book so you have to write it again. Probably a magic book that can't be lost tho.