So from the point of view of a teenage girl, WHY would that be a problem exactly? It sounds like Sue Ellen's friends are complaining about going to another country with no parents around.
shareI think it was more a way of trying to show how all of the kids felt tossed aside by their parents, as the adults pursued their own needs and wants before thinking about their kid's lives. Sue Ellen's friends' parents are probably fairly wealthy (since they can afford to send their children to Europe for a few months). So they probably buy off their kids with trips and things to get them out of their hair. And the teenagers know it. They know the gift is not coming from someone who truly wants them to have a great vacation, but coming from people who want to get rid of them. So a summer in Europe is not very special to the them.
Sue Ellen's mom is obviously not wealthy, but her boyfriend is paying for her trip to Australia while leaving her kids home the whole time. She too feels cast aside for whatever her mom wants. But in the opposite way of her friends.
That being said, I wish someone would give me a trip to Europe. Geeze, not fair LOL