She, at least, has the common sense to wait until they're a fair distance from the others before she goes back to normal; or, at least, whatever normal is for Mari. That's probably the most they can ask for, at that point...she tries to keep her voice down, in case there's anyone lurking around, before she asks:

"Do you think we fooled them? I figured it wouldn't be like me to just stay quiet..."

At least, she's got a point there?