Oh, this brings back so many memories. I was very much like your friend. My daughter could NEVER seem to get the hang of latching on. It didn't matter what we tried, and we tried EVERYTHING it seems. We worked with lactation consultants (multiple) and implemented every idea they had. Couple that with the fact that I wasn't producing much milk at all and it was pretty much a recipe for frustration.
I remember telling a friend of mine that I felt like a failure as a woman because my body wouldn't do what it was designed to do.....I couldn't produce enough milk to feed my child AND what little I could produce I had to bottle feed her because I couldn't get her to latch on. I dreaded every feeding!
After much trying, I had to accept the fact that it just wasn't going to happen for us. I felt like I had done everything I could and that I had to move on to other options. It was HARD to accept, but honestly, it was the best thing for us. After coming to terms with it, I realized how much happier and less stressed BOTH my daughter and I were. Feeding times became what they were supposed to be......peaceful and bonding for us.
I'm not sure how to tell you to get your friend to that place of acceptance, I think we all have to get there in our own time. I think all you can do is continue to be a great friend to her and let her know you are there for her. Keep reminding her what a good mom she is and that it is not a failure in any way.....it is what it is.
Trust me, she'll have plenty of people telling her that she hasn't tried hard enough, or have you tried this, or have you tried that......or my personal favorite....anyone can breastfeed if they try hard enough. YES, I actually had a complete stranger tell me that in public when I was feeding my daughter a bottle!! You being there to combat that and let her know that she is not a failure, or a bad mom, will mean more to her than you know!!
You are being a wonderful friend to her by just wanting to help her. All you can do it to continue what you are doing and be as supportive as possible.