^Jeez, no wear and tear payment for using her personal vehicle? Even the govt manages to provide that . . .
It sounds like you will be acquiring a car for her one way or another. My questions would be: how cheap of a lease can she get? Do they restrict which vehicle it can be for, since they are paying for gas? Or can she decide to drive a gas guzzler like a hummer and they are still fine paying for gas?
With this deal, I would either drive my own beater which isn't worth much, or if she has no car at all right now perhaps shop for the absolute cheapest new car lease I can get with no consideration given to the MPG the car gets. If leasing, I'd plan to surrender the car at the end of the lease unless it was something I really wanted. Maybe a Kia Soul with a 3 year, $239/month lease? That way there probably wouldn't be much to pay in terms of repairs, since the car is new. But I'd only do it if I could get a really cheap lease, like under $300 a month. I hope that makes sense.
Also, she should find a different job . . . could even be the same type of job with lots of driving, but with an employer than either provides a fleet vehicle at their expense or gives a more generous mileage reimbursement.