That's exactly it Chris, and, like Tony's saying with people who have trouble with depression there's this reluctance to let anyone in and interfere in you convincing yourself that you're the problem, no good, no use and it's better for everyone that you're not here anymore.
Very often, like with this poor young lady, they don't want help at all, can't see any reason NOT to die and can't even allow any alternative to death for really obscure, or completely stupid reasons and when you get to that stage there's nowhere else for you, or even think to go for comfort, 'cries for help' simply aren't on the agenda and you see no alternative to seeking oblivion for you. So no - there was nothing that anyone could have done for her as everyone's saying.
Some of us have been at that 'point of no return' ourselves. I was very, very lucky in that I'd worked in a probate registry and seen and talked to people, parents, siblings, lifelong friends or lovers who'd had to come to terms with effectively wrapping up someone's life and they all used to say roughly the same thing...
"I wish I'd known things had got that bad for them..."
"If only he/she'd been able to tell me how sad he/she was..."
"Maybe if we'd known we could have showed them that we loved them and wanted them to stay"
"They didn't seem to be doing that badly, we had a good laugh the last time I saw them...
"I wish they hadn't done it..."
It doesn't work that way for some people and so they can only choose to leave forever. The shock and chaos they leave behind them affects and devastates their families, friends, colleagues and people who are even loosely connected with them, like neighbours (((hugs))), shop-workers they saw every day.
It is terrible that they die feeling that way, but there's an end to their suffering at least. I've thought about dying at times and, perhaps because I know the consequences for those left behind, and that the confusion, hurt and pain is passed onto people I love and care about, and won't die with me
so I would never do it - I hope anyway.
Your neighbour didn't have any hope and so chose to leave. You couldn't have stopped it happening Dotsie (((more hugs))).