I understand what you are saying, my bad!

Our whole family has always dressed for
MNSSHP over the years and none of us have been turned away. I have two teens and they have dressed in Disney costumes at times (Lilo & Stitch and Jack & Sally come to mind right off) and we were never turned away, though we did have an issue once with one of the senior citizens in our group that was dressed at Captain Hook and they asked him to remove his wig and hat. So I don't think the problem would necessarily be isolated to just children. I'd bring a change of clothes and then you can always check your bag into a locker past the entrance.