I think maybe some posters aren't familiar with high school level sports? My dds' have always played softball and they know that softball comes first but many of the teams they have been on have had girls who blew off games and practices for parties or just because they didn't feel like playing. I never allowed that. You join a team and you make a committment to that team. However, I was still suprised when my dd made the high school softball team that there were practices/games during spring break. No excuses. Family vacation? Too bad, you go away with your family then you will sit on the bench. That was just JV, varsity is even more strict. My dd knows that going in. Next year, her 16th b-day is during spring break. She wants to go away but knows that if she is playing ball, then that's not going to happen. I don't presume to know this girls reasons for having a party at the same time as a tournament but it's a party, I really can't foresee any reasons that would be a valid excuse for not delaying it by 2 hours.
Honestly, it says a lot about the girls character.