Okay, I can tell you what I know for sure about Ohio's laws, I recently had to research them because my husband and I split last year and he was threatening to take the kids to another state. There would have been nothing I could have done to stop him, since we were still married, he had a right to take them anywhere, and all I could do if he DID take the kids and run was file for divorce and custody in his absence, win by default, and then go after him for noncustodial kidnapping (which can take, literally, years!)
Please tell your friend to go ASAP and file papers, once papers have been filed, the wife will lose her legal right to take the children out of state.