I don't know what to do

so my very best friend in the whole entire world got pregnant our senior year of high school, she kept the baby and her and the dad were planning on getting married. fast forward until the baby is 6 months old, they still aren't married and late one night I get a phone call from her and she is in tears. I ask what is wrong and she tells me that she is leaving the father of her child. being the supportive best friend that I am she knows that I will stand behind her and back her decision since no one else in her life will. I go over to her house that night so we can talk about it more and she tells me that he is emotionally abusive to her and she can't take it anymore. It's been about two momnths since then and she is still with him and when I asked her about it she told me that the two of them had talked and he was going to try to be better but I haven't noticed any changes. I want to be there for her but it hurts me watching her deny these things are happening what should I do? we are both 19 it is a lot to handle especially because I have never been in a relationship and she has only ever been with this guy