I'm sorry but if you behave poorly you don't get to do nice things or have rewards. If the mom bought the tickets then she's fully allowed to sell them. This 18 year old is more than capable of getting her own money and buying her own tickets and finding her own way to the show and back.
But for real I got a job at 16 so I did not have to rely on my parents for anything. I could but its far more fun earning and having your own money. If she was a brat she got what she deserved.
i feel like all these parents who like to shame their kids online are thirsty for their 5 minutes of fame lol. she could have easily done this without explaining her story/punishment.
Watch Katy catch wind of this and sneak the girl out and get her to the show or something...
Anyway, in my personal opinion thats not good parenting, thats just looking for attention... aside from whatever the girl did, her mom is acting like a spoiled 13 year old by putting it on fb...