Oh for crying out loud it isn't spiteful it is convienent and if the lady had a problem, all she had to do was go over there and ask for them to be a bit more quiet. Frankly, the people next door didn't know she was up all night and frankly since this is a vacation destination and kids tend to get up early, they don't know they are bothering anyone because they are oblivious.
But, if it had been my family and she came to my room screaming like a banshee, I would have called security and she would have had a problem as well.
Just because this happens regularly by different families doesn't mean she gets to blast the next family that does it. The the offendee isn't any better than the "offenders" and she may end up in more trouble that she bargained for.
So stop being a martyr and the next time it happens go over to the room and politely ask the parents to stop the practice early in the morning. If they don't then call the front desk and get it taken care of. In other words, act like the grown up you are.
jeannej