We've been both. I'd pick October. It is HOT in June, and the crowds are even more unbearable because of the heat. At night when the park hours are extended, there are still tons of people.
We've actually been over Columbas Day weekend, and although you notice a slight increase in the crowds, it wasn't terrible. Also, she could plan on the Halloween party, which was a blast!!!
Also, I say take the kids out of school for the extra day....they're only young once!!!
