@Whatthetrolley yes they were there for the next guard change so 20 mins after DB. It made it easy for us to spot them as we knew they were going to be soon after.
@IpanemaChic he is 14, they took Y10 and 11. They seem to have but are obviously extremely tired. They are going for dinner now then will attempt to get a train home. I suspect it'll be very busy though. I think it's a very special experience for them and certainly a tale they will tell as parents/grandparents. I am so pleased they saw the guard change as it looked very impressive on TV.
They walked for an hr to get to the queue then 12 hrs queuing. They left home nearly 18 hrs ago and haven't slept for well over 30 hrs. Grumpy teenagers all round tomorrow.