After filing Form N-400, Application for Naturalization, the entire naturalization process can take anywhere from 5-8 months. This is an approximation. It may be shorter for some and longer for others.
Best Answer Thanks! I assume from your question that you have a court order for child support that ordered your ex to pay the $820 per month. Assuming this to be the case, and assuming that the court did not allow your ex to reduce his payment, you can go back 10 years to collect arrearages.
In some states, child support stops when a child is 18 or graduates from high school, in others, it stops at 21 (For more information, visit Termination of Support- Age of Majority).