This last season of the X-men had episodes that were just not up to the greatest that we had come to expect from the series. This is probably the worst of the bunch.
Jubilee is not old enough to be responsible for that many kids by herself, setting aside the fact that the kids appear to be on some sort of educational group tour, which is not only a bit odd but would seem to suggest the need for another X-men to tag along.
Playing in a series of caverns is not especially bright, or safe, but that is just what Jubilee does when she is responsible for young children.
They get stuck in the cave and water begins to rise, adding drowning to one of the many life lesson, Jubilee is teaching.
Beyond, the illogical premise, Jubilee's powers seem to have been significantly reduced. She should be able to safely blow a small hole through the rock, by using her years of training.
The episode also demonstrates the sharp reduction in the overall quality of the artwork and animation. What about the fairtale? Well, its not a bad story per se and Jubilee is able to place the mutants into a medival fantasy setting, but its a far cry from thte sort of writing that we have come to expect from the series.