No way. Unless you can contact every other single person who is going to be there in advance to check they're happy about it. I'd be really pissed off if you'd arrived with live pox and I was the parent of one of those children.
I would only go if the do was in a private home, not a public place, and all the guests had been advised, giving them the opportunity to decide. Though saying that, asking rather puts the other parents at least in the awkward position of essentially either vetoing you and your family, or missing out on the party themselves.
So on balance - no. Go on your own, but don't take children with you.
YOu could go on your own A night away from pox-y children might be a special treat.
No - still don't think you can go, even if your aunt wants you there. YOu just never know whether all the adults have had it, and then there's the children who you know haven't, and people may have all sorts of holiday plans that don't involve a bout of chicken pox just before the end of term.
It's deeply annoying, isn't it? Just don't think you can risk it - I know all the arguments about them being more infectious before the spots come out when you don't know they have them, but at least at that point if you did infect someone it would be because you didn't know. Whereas if you infect them knowingly, that's a whole different issue.
I speak as someone who had to leave a spotty ds at home last week for a family function. And who is frankly sick to the back teeth of chicken pox and all its associated symptoms, treatments and complications.