Yes, she can sue. Need more facts. Cases are not easy to win. Usually settles, depends on health and medical problems, cost to repair, house's reduced value, if a disclosure statement was provided, etc., regarding amount of damages.
First off, you say "if" I wrote up, you should not be committing unauthorized practice of law nor try to be your own quasi lawyer. Your house is one of your most valuable assets, depending on your equity. You should consult an attorney in your area. The entire document, if was signed by both parties and sufficient consideration paid or provided, needs to be examined. The statute of frauds requires a written agreement, no oral representations can bind the parties regarding real estate matters.
You should see a Nevada lawyer. Was the estate probated? Any Will? The estate is responsible to pay off the car loan, otherwise, the lender of the money will repossess the car for nonpayment. But you should check with a nevada attorney.