Ione is usually very, very cautious about who she impresses and how publicly. Academic high achievers who don't otherwise have a lot of means to defend themselves are prime targets for having tutoring and homework assistance extracted from them. They're usually willing to go to greater lengths to threaten you than you really want to go to defend yourself.
She finds herself strangely unable to resist the prospect of impressing this time, though, and strangely glad that she hung Detect Thoughts today (one of the most useful spells you can possibly have in this environment) and hasn't used it yet.
She casts, her hands underneath her desk, because there's no point in being more public than necessary.