My opinion for what it's worth. Take the pictures down. Model Released or not, you are a photographer that makes money selling images. That means you are a business. A business can not go to court without being represented by a lawyer in the USA. Even if you win, you will lose. Lawyers are expensive and will need a retainer on the first legal papers filed by her. If a model ever asked me to take down their pictures, they would come off my site and I would assure them I did everything I could to help them. Good for her if she made it big...Maybe you helped her with your images. Good karma on your part will go a long way for you. There are plenty of other models out there and if she has a new cosmetic contract, do everything you can to help her and you will see, it will come back to you 10 fold.