Spouse Refusing Mail

My spouse lives with her parents in another state as per our custody order. She has denied me visitation more then once and is failing to follow other parts of the court order. I filed a motion to show cause and sent it to her via certified mail, return receipt requested. She is now refusing to get it/sign for it stating her and her parents “have lives to live” and can not be bothered to go sign for any mail. I can prove that she said that as she told me via Facebook. What do I need to do in order to prove that she refused service, or do I have to find another way to try and serve her?

A motion does not have to be sent via certified mail, you can use regular mail to serve her.