My cameras alert me to movement, but I also have my phone in Sleep mode at night. I don't want to get woken up every time the neighbor's cat walks through the back yard. I don't know what other people do, but I'd be surprised if most people have their phones set to wake them up for camera notifications. And (this might be unverified, so JMO) if NG wore hearing aids and didn't have them in at night, she might not have heard it even if there was an alert. I don't think it is at all a safe assumption that she must have already been disabled if she didn't get and act on a notification about motion at the door.