Breaking away from those I was accustom to and comfortable with was one of the hardest things for me to do. Most were upset with me. Some understood and were supportive. Others still hold resentments, but that's their problem. However, moving on without those friends was/is the best thing for me. I still talk to some of them occationally, but don't go out with them. If I did, I'm quite positive that I'll be where I was back then.
Perhaps after you stop seeing your friend, she'll realize the problem you both share. She may recognize what you are doing and why. Maybe she'll follow your example. And, who knows, after awhile you'll both be best non-drinking buddies. Wouldn't that be great?
After all, if you keep parting, drinking, driving when your drinking, blacking out... you may end up dead. And no one parties with the dead.