10
Get the kid to testify
It mainly depends on the child's actual condition and how old they are.
Age 10
Refer to rsmo 491
The Division of Child Support Enforcement provides child support enforcement in Arizona. It is a part of the Department of Economic Security and is funded by the state of Arizona along with the federal government.
you go to court and testify
Arizona
you can be subpoenaed. however, you can say you do not remember and do not recall for every single question that they ask you.
Arizona Child Support Enforcement will handle it.
They can't in a custody case. They are seen in chambers. see links
a child in tribal custody has asked to speak with the judge of the tribe. Does the child have the right to do that?