I'm glad to hear you're scheduling some downtime! Take care of your health, and remember that theme parks are havens for infectious critters. Consider wearing a mask if you haven't had your shots.
I think that what the artist is going for here is that her expression is changing from very focused, sharp, and hostile, partially because of sleep deprivation, to relaxed and kind. Being that they're drawing cute anime girls with HUMONGOUS eyes with only line art, and that change of expression becomes a bit harder to convey.