Sure, though I'd note that feeling safe is potentially about more than just having the means to make a phone call.

Feeling is an individual thing, though. I think it's better to define safety and try and achieve it (e.g. we want an emergency button to push that pings a location-aware SOS out), rather than making people feel safer (e.g. self defence classes).

Why do you assume making children feel safe isn't itself a worthwhile goal?

Another option in the same vein is a watch with cellular. One advantage is that it's harder to lose.