Be a standard: Your friend knows she's trapped. She's not stupid. She knows there's something better, and deep down she knows she deserves more. The problem is that she doesn't believe herself. He still plays the game of being a victim, and the more you scold him, the worse the service you do. The best thing you can do is give an example. Create for yourself the best relationship of all time and share with her the beautiful moment you have. She will feel this automatically and the change will occur naturally.
The second and most favorable option makes me believe that you attract the same energy that surrounds you, so the best thing would be to surround yourself with people with mostly good relationships, it is the way that this energy traps you and allows that inner awakening that maybe the internet through the blog does not achieve... I like this idea, I have always thought that the situation around you is the one that moves specific energies, great lesson David, happy night.