In addition to the GEICO covering it, the credit card she used to pay for it might also have done the trick. My AMEX covers this so in addition to my normal car insurance, I will make sure to pay with AMEX.

If she was told that she couldn't rent a car without it and she is over 25, then she should fight for a refund. When you're under 25, you're lucky enough to get someone that will rent to you and stuck with the conditions you get. Sad, but that was true when I was younger anyhow..