As a data point, travelling with my daughter we’ve habitually taken her ukulele so she could continue her practicing over the summer holidays (month long).

The advice about being first to board is muy importante.

Along with that I’d advise anyone accompanying the child having their necessities and valuables together so it can be taken out of their hand luggage and carried separately if required at short notice.

We’ve lived an example where, having navigated the check in desk and boardIng gate, we were accosted at the foot of the stairway that led directly onto the aircraft and told to leave our carry on there. This prompted a very short negotiation in which I agreed to give up everything we had but please, please could we keep the ukulele. A hectic anxious flurry ensued with my retrieval of passports, keys, money, documents, the bags abandoned to the hold, and the ukulele claimed its prized place under the bottoms of the passengers sitting in front of us.

I love the calm and comparative predictability of long haul flights.