It doesn't matter if you can go with her or not. When they go in they interview room, it's only going to be him and her. If she needs an interpreter, they will have an officer who speaks her language present. While she can't get in trouble for not talking to him, that leaves him only has the victim's side to go on which could turn out bad for her. Define super far because no, he likely can't just come out to her. What do you mean by "I don't really have a case against her?"

If she goes to talk to him, she needs a lawyer with her.