I suppose the only thing that might have helped Ann or somebody in a similar situation is one of those personal security alarm necklaces or bracelets.
From what I gether, some of them automatically call either an emergency number or some other trusted person's telephone when it detects a fall. My mum has one but I don't think it is as sophisticated as that. I think you have to push the button yourself and how often she actually wears it is another matter.
I'm probably way out of touch and smart watches most likely have some kind of built in personal alarm feature as well, if you set them up right.
Anyway. It's a shame really that I'm even thinking like this. RIP Ann.
Another thing that I've heard - which may very well not be true - is that house insurance won't pay out in the event of a burglary if you haven't properly secured your home. In other words, leaving the window open is asking for it. I've heard this in France though and it could very well not apply to the UK.