So, if you didn't know until recently that they started out human, then you're still learning about them even in your own world.
[She considered that.]
It could still be possible. Maybe you just haven't found it, yet.
I've only been aware of the whole magical world thing for four years myself. I'm sure there's tons I still don't know about.
[Despite being born a witch, having had her powers bound as a child had left her out of the whole magical knowledge department for pretty much almost her entire life so far.]