It's not hard to mirror a smile back at her, saying,

"Well, that's something."

A demon-worshipping cult would be just what Thedas needs, huh — well, another one, anyway. And as to her first statement —

"You have a point. Space travel," relatedly, "is a lot easier to imagine when it's just a reality. Remind me to tell you more about it sometime when we're not in a cursed temple."