This is Samuel and I will discuss this and provide you information in this regard
I suggest you can sue for defamation
. You will want to consider having a mental health professional/family therapist see your daughter to evaluate and determine the "damage" that is being done to her and also to the extent the comments are affecting your relationship with her.
I also suggest that if you could get the court to confirm there is contempt, that would be good to have and use in a defamation lawsuit.
Remember, that defamation is statements made that the person knows are not true, but puts out as absolute truth in an effort to harm another. And if at any time he said "in my opinion" or "it is my opinion" that your Mother... that would not be defamation. He is entitled to an opinion.
If you decide to sue for defamation, you can request the court have your legal fees and any associated costs be ordered paid by him
To help accomplish your legal fees be covered, I suggest you will first want to write him a letter. In the letter you will state that not only is he in contempt of the Order but he is deliberately stating untruths, that he knows to be lies to your daughter in an effort to destroy your relationship as well as to cause you intentional emotional distress. And that if he continues, you are prepared to file not only contempt proceedings but also a civil lawsuit in which you will also request the court order him to pay your legal fees in this regard.
That letter would need to be mailed certified with a return receipt requested so you can show the court you tried to settle out of court and it is only due to his actions that you are in court.
Please note that I can only provide information for what you ask. In that regard, if you have other questions or need clarification, please post them here. Otherwise, I appreciate your Positive Rating as that is how I get credit for my time and information.