Can I keep my wife from getting American Citizenship when I divorce her?

I married her in the Dominican Republic 3 years ago. I have seen her twice since then. She is now in Dallas and has moved into her Sisters house after living with me here for a month and now wants a divorce. She has brought her child up here and has enrolled him in school here. I think I have been Duped by her in order to get Citizenship here.What are my options if any?