2nd DUI, she’s got bigger problems than whether device wasn’t on car.
First, making a DUI mistake more than once is a considered a big deal in most states. Get her a good attorney now. Is it a felony for 2nd DUI?
Second, it’s personally a big mistake. Either alcoholism, or some other reason why the person didn’t learn to get careful. It’s dangerous to drive drunk. And a big deal if you can’t learn from your mistakes on this.
Invest in a good handheld breathalyzer and use it from now on. Save the receipt to show the courts.
Have her call DMV and ask if there’s an interlock requirement on her account. If there is, it may show up for the court. If there isn’t, which may well be why the police didn’t notice, then they’re no requirement. The court will have any prior records of having to show up in court and get instructed in getting the device, so if that happened and she ignored it, the courts will know.
She can still survive this. But only if it’s finally the wakeup call, where she really starts getting the help she needs. 1) on the drinking and driving 2) on figuring out why she’s such a risk taker with the law – it’s not a matter of respect for the law – it’s a matter of respect for oneself. For that, there are counselors that can help. On the drinking, start attending AA meetings at least 2xs a week or more, so that by the time this all goes to court, she can say she’s serious about getting herself help.
She needs a good attorney, and to get one right away.