I'll take your word for it, but the tone of the thought suggests that she doesn't actually believe him.

Pidge takes her place on the other side of the mat, unsure what to do. It would look strange if she didn't offer some kind of comfort, wouldn't it? They're supposed to be a couple, and they have to act like it.

...What would she want Dipper to do here?

Trying to make it look as natural as she can, she puts one of her hands over his. This should make it more convincing.