Emily,

Kat has got a really important point there--you should talk to her, not only about death, but about what she is doing to you--she has got you hook line and sinker, because you care, and the whole deadpan act, "Life is meaningless, and here is what I am going to do to end it" gets the desired response out of you, horror, despair, and guilt, every time--

Part of what suicide prevention/intervention people do these days, is to put the patient on notice that the threats are taken seriously, that it is not a game, and that, no matter what they are feeling, they have to learn to accept responsibility for themselves--

The bottom line is simple--she is trying to make you responsible by refusing to take any action herself, and dumping all the plans and feelings and hopelessness on you,and making you do something about it--

I don't say that this is all a game, and that with a little tough love or whatever, she'll straighten out--there is a real danger that she will carry out her plan(even if she doesn't really mean to kill herself, she just wants the attention) and goes too far--

You are dealing with a person who doesn't accept responsibility for herself. so she believes that other people are responsible for her present situation, and if she does something horrible, it is because others have mader her do it, and therefore that others are responsible for stepping in and saving her--

Obviously your friend has long term depression, some possible causes have been suggested above, and I will throw in traumatic brain injury(TBI), which may have occurred, either detected or undetected, anytime from birth through adolescence, and, because it left no lingering outward debility, was never noted--

Recent advances in brain scan technology allow neuro-scientists to observe both organic and functional damage in the brain, and it is becoming clear that the brains of chronically depressed and TBI survivors show similar irregularities in function--

But the problem is not that there is something wrong, but that your friend has refused to make any effort to deal with it--

She has put you in the responsible position, since she won't deal with it herself--do what you have to do, even if it means having her locked up--in the US, she has already told you enough to have her committed to an institution--

At the risk of sounding melodramatic, after a while,you get used to visiting the mental institution, but you never get used to visiting the cemetery--