Exposing one's sins to people

I have a friend who is in a situation, she is getting married in less than a month Insha Allah. She has made many changes in her life as growing up for her was on the jahiliya path with the wrong crowd and being involved in a lot of haraam things. Now she was in a haraam relationship and it was ended many years ago. She had met this guy who now she is engaged to and introduced the parents were now alhumdulilah are getting on and like I said nearly getting married. My friend committed a sin a few months ago and committed zina with her past relationship. She has repented sincerely and has promised herself not to ever let shaitaan win over temptations and commit haraam again. She now isn't sure if she should be honest with her husband to be or to not expose her sins what can she do?