Relief ISN'T a bad emotion. And superheroing does sound hard. In fact, she's still really tired right now because of it. This is all making sense to her. Sure, she looks concerned, and maybe slightly suspicious at first, but she's nodding along.

She finds it a little strange that he doesn't want to tell her what kind of bad thing happened to him, but something else catches her attention. 'Bigger than Weirdmageddon'?

"Uh, Dipper, what could possibly be worse than the universe getting destroyed?" She says with a laugh that is both nervous, and slightly hopeful. He's probably just exaggerating! Maybe. Hopefully.