Her mouth tightens. Clearly she is deciding whether or not to acquiesce to the request. She can't see him -- can't see the eyes fixed through the glass -- though she feels the tension in his body just outside the pane. She knows he very much wants her to agree.

Alone. She wanted to be alone right now, to have a chance to chew this over, to try to figure out what the heck it means, why it hurts, why it scares her so badly, right down to her very core. No one is letting her have that tonight.

But somehow, suddenly, she's just getting so tired of running. The night is sitting like a weight on her chest, unalleviated, and the heaviness of it is crushing her chest, bending her ribcage. Part of her, unconfessed, wants this out into the open air, if only to relieve some of that weight.

A few more moments of silence hang between Toph and her sifu, and she steps forward to unlock the window.