Children are not allowed to choose where they want to live until they are 18. Many people are surprised to hear that. There is a statute that basically says, if you don't use your time you lose it. I am sure that is the statute your ex is going to try and use to get more support. If you are currently paying 25 percent, then she will not be able to get any more support from you. I would suggest contacting a lawyer to discuss your options.