This sounds like thinking I had as carer for my mother with dementia/Alzheimer’s. If so, I found introducing new things to be not useful, it will be soon forgotten, (If not, good, and ignore this, but XY-Problem indeed). What I found actually useful was remote video monitoring on my phone (using a few RasPi’s, I’m sure there are better solutions, but I was poor, and it worked) allowing me to go out in necessity. The other thing I wish I’d done earlier is reach out to any and all available support earlier rather than later, it’s a marathon and every edge you can get will allow you to do better for all concerned, not least yourself.
That said, watches with automatic fall monitoring, with SMS alert to you would be useful. Ideally, something like Alexa (but preferably not as privacy invading, still, needs must as the devil drives) or whatever allowing her to just call out “help” and get a call to you on a speaker / microphone is probably achievable now, perhaps someone can chime in, or you can go searching. Best of luck!