My daughter has flow to Spain and to Dallas by herself. They will sometimes move the minors to a section of the plane to be all together. That happened to my daughter twice. When coming back from Spain she got moved to first class. They take good care of them so I wouldn't worry.
Just be prepared, They are the first ones to get on the plane and the last ones out. Most airlines request that you stay at the gate until the plane is up in the air. With my daughter's trip to spain, they had a back up on the runways and I was there waiting a good 2 hours.