This is an issue between your husband and his ex. You would not have standing to seek restraining order for yourself. I would, of course, strongly recommend that you terminate your attempts to contact the ex; it could possibly considered harassment and she would have standing to get a restraining order against you.
Since you are uncomfortable with the communications between the woman and your husband, you need to talk to him about it and express your concerns. If she's communicating with him in a fashion that is outside what the court ordered, and if he's concerned about it, he might want to go back to court to modify the existing orders or to seek a contempt sanction against her.
The answer to your question is not intended to provide you with legal advice you should rely on, only a general indication of what the law might provide. You have provided only a limited description of your situation and I may be unaware of important facts that could affect your case. My answering your question does not create an attorney-client relationship between us.
First of all cease all contact with the ex. This is a between the ex and your husband. You and your husband need to sit down and discuss the way he communicates with her and tell him to go by the court orders that are in place. If the ex refuses to abide by those orders then the matter needs to be taken back into court for enforcement or modification through an OSC.
I know you are doing what you think is best for the child but your husband is the one who needs to be doing that. I know it's hard on you and that is why you and your husband need to discuss matters as well.
Note this answer does not constitute legal advice, and should not be relied on. Each situation is fact specific and court specific, and it is not possible to evaluate a legal problem without a comprehensive consultation and review of all the facts and court pleadings filed in the case. This answer does not create an attorney-client relationship
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