Everything for us was walk on, I didn't see Peter Pan, but when we walked by Dumbo was walk on and Alice was maybe a 10 minute wait, like PP stated. Even SM-GG was walk on which surprised me because last year it was about a 10-15munute wait....which was still amazing! HM was a 15 minute wait, definitely not a long line. I have a feeling your 9 year op will want to do at least a few treat trails. Avoid the ones when you first walk in, the line died down considerabaly as the night went on and they all moved very quickly. The one in the goldenshoe was really fun, great decorations.
we did all the headliners and saw/ waited for the parade and still had time for lots and lot of trick or treating. Have fun!
I wouldkeep an eye on the app too, if something has a longer line, skip it and come back.