Looking for Alarm System

Hello All,Last night, my mother-in-law passed away unexpectedly.She grew up in a farm area with few neighbours who were more than a few miles distant.Her residence is currently unlocked (door locks only), and we are concerned that estranged family members may attempt to remove valuables.I need an alarm system right away, but it has to be good. The property has excellent mobile service and is equipped with ISDN and WiFi.I read several web reviews, such as [this](https://techsherlock.com/simplisafe-vs-ring-difference/), and wanted to hear about your experience.