I do understand most of you don't like second shower or sprinkle, but why would you attack the host! I understand attacking the mother who expects a shower, but attacking the host?
Maybe I am naive, but I think the host felt it was ok to throw the shower (ok in their circle) and offered to throw the shower on her own not being forced by the STM to throw the shower. If any of the guests have fundamental issues with second shower will decline the invite.
OP, Since it's coed, I would do the following:
Beer, non alc beer, and mini izze cans of drinks
finger foods, like wings or meatballs
pretzels or bar mix nuts
cupcakes