From 1 experience,
Some queued for hours beforehand, allegedly. Presumably for good seat. There's no need as once you have a ticket you are guaranteed a seat.
Once you have seats either you or your mother could leave the theatre and return.
It is very busy as it's a full house, but not chaotic.
The show we saw was very good,
1 hour and not too much waffle, he had his own band with him.
Good luck with the raffle.