Good. Android supports multiple profiles, and iOS does not. Google work profiles for Android, and you will see how this can work, and how to set it up.
Basically, you create an additional profile on your Android phone for work, or whatever other purpose. In that profile you will have Google Play store, and can download any duplicate apps you want, such as Blink home monitor. Once you have Blink home monitor installed in the profile, you can log in with your grandmother’s credentials, and you will have two separate, running, instances of the Blink app, for which you will receive notifications for each.
When you get a notification from the work profile, selecting it will take you directly to the work profile on your phone, and into the Blink app running in there.
I have used it under test for Blink, and it works perfectly. I now use it extensively to have a whole bunch of duplicate and separate apps for my mother, who hasn’t a hope in hell of operating a smartphone, so where it is now almost essential you have an app, such as for banking, I can do anything I want for her in that profile. All log in details etc are retained, as though you were an entirely different person when you are in that profile.