It all depends upon what she's done or is thinking about doing. If it's not something that she would have done when she was sane/rational, then there is going to be guilt associated with the actions.

Have you ever done something and knew it was wrong and yet you did it; but when you looked at the person you did it to, guilt set in?

In their minds, they know that what they are doing is so totally wrong and yet they are out there behaving in a manner that is not becoming and in most cases morally wrong. Deep down they know that they are doing it and yes, they know that they've hurt us and our families. Guilt sets in because they know that they've done wrong.

I can't tell you what kind of guilt your wife is experiencing, but if she's acting off the wall, lashing out at you or going off the deep end, she could very well feel guilty for taking it out on you and behaving this way. Guilt is knowing that what you are doing is wrong and yet you continue to do it and it hurts others.

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.