What is the guidance and advice of religion for someone who remembers his wife's emotional past before marriage, and how does that affect their current relationship, despite the husband's acknowledgment that his wife loves him and treats him well?

What we advise you to do is to live with your wife in kindness and be a good companion to her. Do not pay attention to those satanic whisperings through which Satan seeks to cause discord between spouses. Beware of going too far with this thought, seek Allah's help, and cast away those whisperings from yourself. And know that a person is judged by their current state, not their past, and repentance wipes out what came before it. So, be keen on this wife who loves you and spares no effort in serving you.