No insurance company with half a brain is going to beleive that she is the legitimate owner of a car which:
a) You used to own and were driving under DOC at the time a claim
b) That she isn't legally insured to drive herself
c) That she never drives and is outside the typical vehicle type for her demographic
etc etc.
The loss investigation team would be all over your claim like a rash.
You know as well as we do its your car - you are just trying to find a way around having to insure it like everyone else does.
Fraud = obtaining funds by deception. In this case, the funds are the money you'd have to spend on insurance and the deception is the charade that its owned by your girlfriend, when in reality, we all know it isn't.
JUST INSURE IT PROPERLY