Given the reasons for the custody award stemming from an act of violence by your son's mother two (2) years ago possibly she has taken the required anger management courses and satisfied them assuming such were mandated warranting the possibility of a change in the present custody arrangement that you have written about.Given what you have written about you should consult with a family law attorney about the possible motion to modify the current child support order by your son's mother and how to confront it in that she may have changed her ways warranting a change in the status quo.