I forgot: the sequel to this. The girl didn't kill herself, and I don't think she's going to now. I asked her what stopped her, and apparently I had telephoned her mother to explain why she was not home on time, so her mum wouldn't worry. I'd said all this on an answerphone message. Poor kid tells me next day she'd played the message over and over again, and as a consequence, hadn't done anything stupid.
It's incredible how much of what we do for each other is down to chance.