Discovering she could do it, probably by accident, would make her unhappy, and each ascending level would make her unhappier. Especially given the spells she acquires.
Except of course -- RPG -- it's a role. The player can assign a class and choose to go up a level in it rather than something less fraught, like, say, rogue, and pick and even replace spells. From the gaming point of view, she can panick at all this mysteriousness. I think switching spells would probably frighten her the most. . . and there lies plot. To be sure, with the players not even making a hint of an appearance, the reluctance does push it away from the center of GameLit -- but who needs to be in the center?