I just wanted to offer hugs first and secondly just to give you another angle.

My husband's daughter went through a faze (for want of a better word - sorry) of saying she wanted to die and thought about killing herself.

In her case it was manipulation and a cry for attention. We know this because she was seen by a counsellor who concluded that she exhibited none of the danger signs (paraphrasing here) and was just seeking attention but lacked the emotional maturity to fully understand what suicide actually was.

Maybe your daughter has heard of suicide (an off-hand comment of, I just wanted to kill myself either IRL or television) mentioned it to you and seen the reaction.

I hope you don't think I'm discounting your situation and fears - I just wanted to offer up something we had experienced.