As long as she can participate in our daily activities, and she is not in discomfort, I would have her. But as kangaroomama said, if she can't; she may be better off at home.
I would let parents know that it's not contagious. Don't give details, that's none of their concern. But it is their concern as to whether or not their child is being exposed to something, so I would put their minds at ease.