with your friend - could you suggest her giving a call to lifeline?? they will be able to assess her immediate risk, and also refer her on to services (if she wants them) that might be useful for her. the number is 13 11 14 (20c local call).
your question is an important one, but if it's been raised because your friend has recently spoken to you about it, then my first concern is that she get appropriate support to help her with these thoughts

.