I'm sure you've already considered the "Hire a Lawyer" thing, and concluded it is cost prohibitive. Best result though?
You can go in and fight this, taking your (and her) valuable time. You've considered this as well, I'm sure.
That last step is perhaps, the only practical step. Some things to consider:
1. No one in court will give a crap about your numbers. They are too stupid to understand them, and they've heard it all before. Worth a try, anyway?
2. So you know, a human being (a sworn Police officer, in fact) has checked and certified this (prior to it being sent out).
3. I want to make a comment on the plate reading technology, but cannot, except to say that it is not the weak part of their argument against you (if it has any bearing at all).
4. Reference comment one, above. A human being had to check this, and certify it. Did they make a mistake? You can certainly question it.
5. Most guilty verdict traffic violations are overturned on appeal.
Good luck, I'm rooting<sts> for her.
FM