Hell isn't that big of a deal. Warned or not its no reason to hold a diploma. What I can't understand is why she and her dad really care that much. Graduating high school these days basically means that you successfully inhaled and exhaled for 4 years straight and she will be attending college anyway. So held diploma or not its practically a moot point. I think it would be hilarious is they just told the principal to go F*** himself and leave the precious diploma at the school indefinitely while she moves on with her life.
although i did graduate HS, college only needed a HS transcript. Sounds like a rotten deal.