I might buy "making a mistake" if she had been pulled over after having three glasses of wine over a 2-hour dinner and she was barely over the limit. This woman DRANK before driving a busload of school children. That wasn't a mistake--that was typical alcoholic stupidity. Her life has become unmanageable. She needs to SEE that, to OWN it, not pass it off as a "mistake."
I'm a retired prosecutor. If she landed in my courtroom I would insist on some jail time--maybe weekends or the trash-pickup deal (wearing orange), unless she screwed up while on probation, at which point she would get REAL jail. And it's not all about what she "needs"--there is also the need to deter others who would otherwise see this as "not that big a deal."
That's the bottom line in this situation. It isn't all about HER. She hasn't gotten that message yet.