Hey, personally, I listen to my gut on this kind of thing.

I'd let them THINK that she's going, and then, if you feel it just isn't a good idea...

you DO ultimately have the authority to not send her. Send a note excusing her due to "illness."

(They don't need to know that this means... I felt just SICK about this activity when I really thought it through... )

Schrödinger's cat walks into a bar. And doesn't.