COMMENTS:
Voted : Comment
First I would attempt to determine if she was exhibiting suicidal ideation or suicidal planning. If she demonstrated a plan to kill herself, then I would do my best to help her--including contacting the authorities. If she said she wanted to kill herself and posted pictures of self-mutilation without a coherent plan of action, I would still try to help but *probably* wouldn't be concerned enough to report it--particularly if she was a complete stranger.

Frankly I think anyone who has never thought about suicide in their entire life is suffering from a greater psychospiritual deficiency than those who have. (Of course that's just a generalized opinion; everyone's different.)