In today's western world we don't send the wife of a murderer to prison too. It's bad enough for her to be married to him.

Of course not. However, if the wife of a rapist takes action to shield him and to attack and besmirch the women that were his victims, then she is culpable for something. IANAL but I think that she would be guilty of some crime (maybe aiding an abetting? I don't know.) So, obviously the wife of a rapist should not be sent to jail with her husband the rapist, but she should be held accountable for the crimes she committed while trying to cover up his crimes for him.....