She's not going to get in trouble unless they prove she broke the law. It's not a huge issue and she will be embarrassed by it.
But don't 23 year old educated women understand basic risk management. I understand when social media first started people didn't get it but now you should know.
i have tons of friends tweeting about and posting stupid poo publicly on their facebook walls all the time. like people in their mid 20s who should know better at this point.
i mean it's just common knowledge now that if you're in any form of contact with an employer for a job opportunity they'll be internet sherlock holmes-ing the hell out of you.