No matter what she says, he has a right to see the kids if he wishes. If the divorce agreement grants him visitation, and she denies visitation, she's in contempt.
If he doesn't want to see the kids any more, then he should sign over his rights. He'll probably regret it someday, but he could do it, being married or not. It's common that court proceedings happen with people in different states, she could attend court by phone. You could just file yourself at the family court to save the lawyer's fee.
At some point down the road, he can have the child support modified. Wait until she gets married, as she would have more income at that point. Estimate the calculation yourself, if it's in your favor go back to court: http://www.alllaw.com/calculators/childsupport/illinois/





