I'm not sure what you mean. Is she saying that you aren't paying all of the child support that's due?
Child support is ordinarily paid through the state child support trust, and if you've been doing that, then there should be no problem in proving that.
If you have been paying her directly, you might have canceled checks (or get scanned images of canceled checks from the bank) or have bank statements that show the designated amount.
It sounds like your wife has filed a petition to have your support payments reviewed by the court, so if you're not quite sure what to, consult with a family law attorney to help you put together the proof you need to make your case at the hearing.
Why would she file papers saying the support was lowered? Is she paying you? If so, this is why she probably said that. She doesn't want to pay as much. Generally, when any case has changes, a hearing is to happen in front of a judge. Go to the hearing and deny any change that she said was made by you. Ask for her proof. If a notorized form with your signature isn't produced, the judge won't likely believe her. Many people try tricks all the time. Judges are trained to spot them. Ex wives and ex husbands usually don't agree out of court to reduce the amount of money they want to receive from the other.
If she did file something, go to the clerk of court of that county and ask to see it. You will have to know your family case number, or have to pay a minor fee for a search. Look over what she filed carefully, but don't say anything incriminating to the clerk. Remember, they do work for the judge. You can ask them for copies, and to see your file. They won't give you advice. You may want to consult a lawyer. Someone who doesn't have a part in the case can usually keep the facts seperated from emotions. Remember to act professionally, and respectul. You will benefit from that.
