If my ex-husband is behind in child support/alimony, what rights do I have to an inheritance of his?

If your ex mother-in-law is deceased and your ex husband is selling the house, he most likely has the right to sell the house and receive the money. If you already have a judgment for child support and spousal support, then it is possible that you can either:

(1) receive from the court and record the Abstract of Judgment on this property (if it is not in escrow yet). This way, the title company probably will not allow the sale of the house unless you are paid off.

(2) receive from the court a Writ of Execution on the judgment and serve this Writ directly on the escrow company. This way, they might be required to pay you the money to which he is entitled.

Please note that both variations above are only general possibilities and are contingent on your ex having a right to the property or to the proceeds from the sale. You definitely need to contact an attorney and receive a legal advice that is applicable to your specific situation.

A court ordered divorce decree is enforceable like any other type of judgment.  Similarly, child support is also enforceable upon an ex that fails to pay.  If the person that is not complying with a court order is asked to comply, the court may permit the party seeking to enforce an order by securing assets.  In this case, your ex has failed to make payments to you pursuant to a court order.  While you pay child support, he is still required to pay money if you sought and obtained a child support order.  Back child support may be ordered.  If your ex is going to be receiving the funds of a sale of real estate, then you need to file a motion in court and ask the court to enter an order to garnish any monies he will receive.  You ex is not the owner of the home but rather a beneficiary. If you tip him off that he is going to have this money taken, his mother may figure out a way to keep you from taking it. Thus, it may be best to wait untill he gets the moeny and then execute on his bank account and tie up his assets and threaten him with jail time for his violation of any court orders.  Hire a lawyer if you can afford one or file a motion for contempt and explain your grounds to the judge.  Divorce court is a court of fairness.  The court will do the right thing.