So, if she were asked the question, should wives submit to their husbands as the Bible commands, you'd tell her to avoid answering the question? I don't think that would go over to well with Iowa evangelicals.
If I were asked I would say something like this.
“I’m not running on religious issues, even though I may share many beliefs with the people here. I am running because we have a man in the White House who wants to strip us of our freedom to practice our faith as we see fit, like he has attempted to strip us of 2nd Amendment rights, like he HAS stripped us of or freedoms to choose the health care we as a free people once enjoyed.
In short, it is not the business nor the place of the President of the United States of America, nor a candidate for that office, to tell families, Christian, Jewish or secular, how to run their homes.