While the Texas Attorney General's Office child support division does fairly well in most cases, this case involves another state, and the Texas Attorney General is not an official of that state.
I hope a New Mexico attorney will comment on this question, because with the dad being in New Mexico, that is where he can most easily be tracked down.
Your best course of action is to get with a Texas family law attorney and lay out the situation and get advice specific to your situation. That lawyer may suggest getting an attorney in New Mexico. But, with over 10 thousand dollars on the line, it may be worth it.
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