On Childswap, what do you do when you are not sure whether you will need Childswap or not until you actually get measured. My DD is 39 1/2 inches so I was guessing that it was 50/50 she would get in. Do we all wait in line the entire time until we get her measured and then if she won't make it, then ask for the childswap then? How is this different from the ride we know she will not be tall enough to ride? Is there a different person we get the childswap ticket from then?