C.G.
I'm not sure about the restraining order but it can be put in your temporary seperation orders. I put in mine that my husband wasn't to take the children around his girlfriend (at the very least) until the divorce was final. Just keep in mind that he can put the same restrictions on you.
I would assume to file a restraining order or put it in your actual divorce decree there would have to be some sort of evidence that showed she could be harmful to your children...otherwise angry ex-wives everywhere would be making such claims whether founded or not.