there have been reports of this befoe on PERB and usually something the gals does or says or is carrying give away her situation. One Sp drove up to the Blaine border crossing a few years ago and said she was going to Vegas, alone. Her suitcases were opened and her "work" clothes found, and she got a four year rejection on the spot. If you buy an airplane ticket and use a work published phone number on it, or they can make any connection to SP work at all, you a done. However, many gals get away with the situation, just don't hit a border guard who twigs onto the item, and I know a couple who have crossed the border regularly without detection for many many years. But then too, having a regular job or fall back in that area makes a big difference. If you appear to be unemployed when asked who you work for, have a suitcase full of condomns and work stuff, going to the wrong destination, like maybe Vegas, etc, the border guards are very likely to spot the situation. Like anything else, some make it, some don't.
She might just as well forget trying to enter the states again for at least four to five years, permit or not. what does she have to appeal on? She likely can't back up a legitimate position at all...no real job, no income here, etc..
The other advice, if she wants to vacation, take direct flights to Mexico or other destinations that don't stop in the US. Just stay well clear of the place for several years.
Next advice, get out of the trade, get a legit job, have a boss, income, home, etc. and this can be overcome. But a waiver just isn't in the wind until....