Pls share your Custody experiences in NJ when DV & alcoholism is involved

Just wanting to hear your experiences. I am asking for a friend. We are working on her meeting with some lawyers but wanted to see personal experiences in the mean time. She has multiple kids under age 5, is an amazing mother, but she is unfortunately in a bad situation. He is an alcoholic & has been emotionally abusive for years (cursing her off in front of the kids, screaming, belitting her calling her stupid, so on and so forth)- it now became violent. She was bleeding and went to the cops immediately. She is terrified if she files for divorce he will get any custody, and she wants her kids safe. He doesnt even care to be with his kids but would certainly fight it out of spite, so she thinks staying in a dv situation knowing she will always be with her kids is better than leaving:( trying to gather success stories of leaving. Thank you.