I have a court order for a dna test and the mom is trying to stop it from happing is there any way she can stop it from happing

Not really, unless she gets the court order over turned.

If she refuses to bring the child, go back to court to hold her in contempt till she provides the child for the test

not really, unless she gets the court order over turned.

If she refuses to bring the child, go back to court to hold her in contempt till she provides the child for the test

How can she get it over turned

By going to court and proving you aren't the father. Or acknowledging you are.

Or that the motion you made was improperly filed, or the legal service was improper, that is why attorneys make 300 dollars a hour ( well some of them) or 100 dollars a hour for others,

They can drag things out, find ways to stall, try to out lawyer the other side.
Court and law is not really about "right and wrong" as much as following the written law with evidence that is submitted according to the rules of the court.
The courts do not do the "right" thing they do the "legal" thing

- And this is why in my State (NY) and some others child support starts when the paternity action is filed IF the person tested IS the father. Keeps the mother from dragging her feet and the father (if he refuses) is held in contempt.