Right, and they do it for a reason. Sometimes it's that they are losers who just don't want to pay support. (Maybe that's the case here. Don't know.) But sometimes it's not.
Moreover, I'm not saying that she should not whole-heartedly seek a resolution from the court. I think that seeking the court's help is the primary thing to do. I'm just saying that trying to resolve a conflict exclusively in a courtroom--where people are stifled by process, expenses, deadlines, and attorneys taking potshots at each other, constantly erring on the side of false accusation and generating ill will, etc.--might not be the only option.