Another one who is butting in and you may have tried this too; please ignore me if you have. My mum was a night-time wanderer/sundowner and her care home used to give her 2 paracetamol before bed. I was surprised when they told me that this is what they did, but, apparently, it helps PWDs to settle.
I have tried this Canary, but it did not seem to make a noticeable difference, although I have just given her 2 because she does suffer from back trouble - probably down to all the walking/wandering she does and prolapse must be giving her some pain. A year ago I was giving mum some night nurse, this helped, have not done this for a while, but may just try some tonight, if she is in pain at bedtime it will at least help.
We both had an hour's sleep this afternoon, I doubt if this will make any difference to sleeping tonight, we were both so tired and I could not keep her awake to try would have just been cruel and anyway I needed some sleep.