My mom's mortgage

I just wrote a loan check of $500 to my mom so that she can pay her mortgage this month. My mom's estranged husband was ordered by court to pay their mortgage until their divorce is finalized, but he has not paid any dime. I am very angry at my mom's estranged husband for not taking any responsibilities. We really should not be suffering for this...... We have been supporting my mom with her attorney fees as well for the past year. Although we are expecting to get our money back after the divorce settlement, we are not sure if her estranged husband is going to follow the final court order. It will be interesting to see what will happen in their final divorce trial. I just want this whole thing to be over soon. Please wish us luck. Thank you.