Are you really asserting here that after researching "how to draw up a contract" that one was prepared and signed stipulating that in the event of default title to the car becomes automatically vested in you? If so, it seems most inconsistent with your statement that she "offered the car as collateral"; (that is, the vehicle was to be pledged to secure the loan), nor the presence of your name on the title as 'lien holder".
I suppose that such would be permissible inasmuch as the debtor in a security agreement can following a default agree to divest themselves of ownership in the collateral in exchange for full or partial satisfaction of the obligation (See: N.D. UCC Section 41-09), but I suspect that what you have instead is an agreement granting you a security interest in the car with your rights in the event of default governed by North Dakota's Uniform Commercial Code.
If you agree that your position is not that of an owner of the vehicle because of the default, but rather that of a secured party having a security interest in the car and wish to know your rights under the UCC, then ask.