I might let my DS attend such an event if he had a slight cold and if he wanted to do so, but absolutely not with anything worse. If he has a fever, he isn't going anywhere, full stop, end of story. I don't think it's good for him, and I don't think its good for the other people, some of them more vulnerable, who are exposed to infection this way (you can cut the risk by trying to stay apart, but not usually to the same level the risk would be if you simply stayed away). More importantly, I would hate him to grow up into the kind of adult who thinks there's something noble in struggling on when you're ill, since I think there's far too much of that about and we'd all be better off if more people stayed at home and looked after themselves when they were ill!
In this particular case, if she's ill she's not likely to do herself justice anyway.
So yeah, sorry, I don't think you should have her do these things if she's ill. Of course, young children do sometimes recover amazingly fast, so if she wakes up raring to go tomorrow morning, that might be another matter!
