What would this make you feel/think...?

So I could tell for the last couple of days that something was on my girlfriends mind. We have been friends for years, dating for a while and are very serious. We have picked out a ring and and looking to get engaged this summer. Last night I asked her to tell me what was on her mind. She confessed that her ex, father of her child, had texted her late last week and told her how sorry he was for having treated her so badly, how much he regretted never listening to her, how he was sorry he never supported her or got involved with their child. He also told her that his current girlfriend is just a distraction for him and that he misses her. While they were together he cheated on her several time, stole money from her, made her leave the house to study because he wanted to be loud, he was an all out ***. She told me his messages did mess with her head a bit, but she said only because she doesn't want him to hurt...said she wouldn't want to be the cause of anyone hurting. I told her his actions are what have caused him regret and what caused their demise. They broke up about a month before we got together. So I appreciate her telling me everything that was on her mind and I think she was totally open...I don't worry about her going back to him ever, but it bothers me he can still hurt her. What would you do/think? I am going to be there for her and offer her advice when she needs it, but I don't think we can move forward until she can get let go of his emotions having such an effect on hers.