SE GPS + Cellular Watch

My Mum is looking for a device she can rely on to call for help if she has a fall on her farm. I wanted to ask how effective this feature is on the SE GPS plus cellular watch on a farm that has cellular signal at 2 bars in some locations and up to 5 bars in others? I also wanted to know what actually happens if she would take a fall - does the watch detect the fall and there is a voice prompt that asks if she needs help or does she need to activate after she falls? Can the help be set to contact family as well as emergency services?

Thanks

Paul