The outpatent therapy and AA meetings are great. Does she have a sponsor to contact and work the steps with? These are all actions that will, in time, allow you to decide if you can trust her or not. She's only been home for a few days so there's no way to know if she is going to be consistent with this. In the meantime, your children's safety is the most important thing. Quitting benzos is not easy and there is always a chance that she'll relapse, but you might not know it for a while. Addicts are very good at hiding these things. After all, you didn't know she was taking them in the first place, right?
I hope you will realize the seriousness of this situation. It was pure luck that none of the kids were hurt the first time she had a wreck. I wouldn't be willing to allow my children in the car with her for a long, long time, and then, only if she actively maintains her recovery with no slip-ups.