The monitor does make it distinctive. If he turns it on and lets her play with it, he may discover she's not having a problem with the languages. And, truth is, she's been given something that translates for her--it would never be a problem for her to understand the languages of his galaxy. But it's magic, and he doesn't like magic, so she's reluctant to mention it.

She looks faintly concerned when he rubs his eyes, not sure if he's frustrated or tired. "Well, I'm good at math, so I should get along with this one real well."