The divorce decree is not "invalid" because of your wife's ex's death. However, the obligation to pay child support may have terminated because there's no longer a living payee who could seek to enforce the obligation. However, the laws in many mid-Atlantic and northeastern states provide for the possibility of child support well into a child's adulthood, so your wife would be smart to consult with a family law attorney in New Jersey about this and, if necessary, how to terminate the payment obligation formally.

