What does it mean when I dreamed about you leaving your husband?

The question is confusing as it is stated. Your dreams are about your own thoughts and emotions. If you dream about someone else leaving her husband, that is about your own marriage just as if you had dreamed of yourself leaving your husband. In both cases, the dream shows that you feel the need for more independence. This might be a good time to give some serious thought to your marriage and to have some honest conversation with your husband.