Post nothing more on a public forum and hire a criminal defense attorney who can help.
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Mr. Kaplan has it exactly right. A skilled defense attorney CAN help minimize the negative consequences that you both fear. Most who participate here will offer her a confidential initial consultation without charge. She needs badly to take advantage of that opportunity to speak privately with one or more suitable lawyers about this situation. Handling it on her own is an even bigger mistake than what occurred inside Kohl's. It may require notifying her parents. I'm a parent and parents are entirely capable of supporting a child who has made a mistake. We have to do it with every one of our children as one point or another. Good luck.
Your girlfriend first needs to talk to her parents about this. Then, she and her parents need to speak with an experienced criminal defense attorney who can help to minimize the consequences of her juvenile act. Good luck to you both!