That is heartbreaking. It's horrible to feel as if you're just standing by helplessly, but unfortunately you are. If she can't see it, there is no help for her. For some reason she thinks she deserves to be treated this way. I put up with a lot of emotional abuse in my second marriage-he would yell and throw things and break things-always my things. I never realized until I got into Al Anon that it was abuse. My thinking was that he never hit me, so it wasn't abusive.
Sometimes age and maturity can get us to a place where we can see that we don't deserve to be treated that way. I would say continue to let her know you're there for her, the offer to get her to a shelter was a good idea. Also the book Women Who Love Too Much is an EXCELLENT book. I hope and pray her eyes will be opened and she will begin to value herself. And also that she won't bring any kids into that poisonous environment. Makes me shudder just to think of it.
You're a good friend. She's lucky to have you.