Legal Question in Family Law in California

Re: Childsupport

File a motion with the court to change custody to your sister rather than your ex-wife. That will stir things up; either she will take your son back where he belongs with her, or the court's intervention will correct the problem.

Good luck.

Re: Childsupport

You should discuss the matter with an attorney. Although you can file a motion to change custody to your sister, that may have an unwanted consequences. If mom requests custody, it is very probable that she will prevail. You need to review the facts with an attorney to determine what your options are and the likely results of any course of action.