The one thing you might want to consider is that if she stops paying on the loan, you will have to make the payments because if you don't it will go against your credit. The lender will only care about your contract with them and it won't matter if you have a contract with your friend. Even if she signs a contract with you stating she is fully responsible for the car, it will not hold up against the lender. If payments are late, they will put all the blemishes on your report.
In addition, if she skips town and stops paying, you will have to continue paying the loan. Worse yet, if she leaves and you can't find her, the lender will want the balance from you. The only way you could get money from her would be to take her to court and show the contract. Even if you win, the lender will NOT remove any blemishes that were incurred.
I don't know you're relationship with your friend and I'm certainly not trying to say anything negative. I am simply letting you know the extent of damages that could happen. The only way she will be "fully responsible" for your loan is if she gets a loan in her name. Regardless of what she signs with you, the fact is you are fully responsible for that car as long as the loan is in your name. I hope this helps.
Lead Developer for The Auto Evaluator