Having child support and mediation issues?

Ok, so my husband pays child support for his son, (not mine, he is from a previous relationship...one nighter) she can't stop going back and forth demanding he have visitation, then saying he can see him cuz she wants more money on top of child support. So we went to a mediator to have her served with a schedule to agree to. We do not have her address. They said they do not look up addresses and the child support department will not share any info with the mediation dept. So how are we supposed to get it? His lawyer told us the only way is to give her our address and hope she gives hers in exchange. But that is not fair, we dont want it, just want the mediator to have it. And I know she will not give hers in exchange. And she is a stalker, she has done crazy things before!!! Dont want her with our address! How do I go about doing this? Is the mediator leaving something out? How does this usually work? I live in oregon. thanks.