Any car with only a seat for the driver! You don't mention her age but teenage girls are rated worse drivers than teenage boys according to insurance companies. No passengers, no distractions, I'm assuming she is a teenager.
I came from a larger family, long before we reached drivers license age we got the "you want a car get a job speech". We all had jobs, bought our own cars by 16, and 7 of the 8 of us bought 1st homes by the time we were 25. I bought my 1st car at 14, a '68 Ford Thunderbird that had an awesome "wraparound sides" rear seat
I didn't bother getting my drivers license until after I graduated from college but I did have insurance from 16 on.