When to file contempt charges??

Asking for my husband. My stepsons mother lost custody to my husband when baby was 4 months old. Well my husband got temporary custody in February 2013, when his son was 4 months old. Then he received full custody in August 2013. The mother gets no visitation and is ordered to pay child support, half of medical fees, and take 4 random hairl follicles over the course of a year and pass all 4 to modify visitation.
She has already missed one drug test, which counts as dirty. She has paid no child support, no medical fees, and refuses to give us a current address so we can have her served for child support. They've had a hard time locating her.
Should my husband file for contempt? Or is it even worth it?
It states in their papers that both parties must give notice of a change in address or residence. She keeps saying she lives at her sisters or grandparents, which we know us not true because we talk to them and go to their homes. She lives with a boyfriend and refuses to share this address or even the town.