I thank you for this post as there is always someone out there that maybe you should be cautious with.
I have only been here for about a month now, and have had tons of people come to me looking for advice (didnt really know I knew how to give advice as I came here looking aswell) But it turns out some people may find comfort in talking to you and if you say one wrong thing to upset them or if they get clingy.. it could turn into a bad situation. I think everyone needs to be cautious about how others feel when on the forum. Sometimes we try to help not knowing the full situation. Keep your minds open but at the same time keep your guards up. I think the point here is to try to make friends ... not enemies
In this case, maybe you could just tell her you are sorry and that you are running out of options and ideas on how to help. Maybe you can tell her that it hurts you to hear her talk like that and if she wants to continue to be friends.. she needs to take care of herself and get help. If she doenst respond to that then maybe you must let her know that you can longer help her, and just leave it at that. Its a tough world out there and we cant help them all. All we can do is be there for people that want help. Those who do not want help... there is nothing you can do until they admit they need it.