My name is XXXXX XXXXX I'd be happy to answer your questions today. I'm sorry to hear about your situation.
The judge will listen to your daughter if she wants to testify. It would be better for her to either appear at the hearing and take the stand or talk to the judge in chambers than to send a letter, because he'll want to know that it represents how she really feels, rather than that she wrote what a parent told her to, or someone else wrote and told her to sign it.
If there is evidence that your ex is hiding money, the judge will consider it. It would depend on why he is sending money via MoneyGram and what is happening, but if he's hiding funds, yes, that will be considered. There is nothing in the law that requires you to account for every penny spent on the children, and no judge is likely to approve that request. Are you supposed to take pictures of the kids holding the electric bill? A mortgage statement? That's just silly, and the judge isn't likely to allow it.
You have the ability to present all of the evidence that you have that he is hiding assets and income. You can also ask the judge to enforce the state's recommendation. If they already did the investigation and can substantiate the amount that is owed, that should help significantly.
If he hasn't filed taxes in two years, you can report him to the IRS.
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