Tone and language is important when talking to people in my opinion. Is your wife cursing and yelling at your children? That is a bonafide concern. Many find themselves able to do for their children what they are incapable of doing for themselves. Perhaps the answer to your problem is convincing your wife she is hurting her children. I, loads of people, and loads of experts can tell her that having contempt expressed at children causes adults with problems. Convince her of that.