Yeah I don’t know that much about it either, but I thought they were just little gps devices. either way, OP didn’t say they wouldn’t have a phone, just that they were not trying to text or answer calls.

if your mom is an apple user, an airtag? I am not familiar with the alternatives but the year old article could help you find a similar item (it compares tile, smart tag and a few others): https://www.androidauthority.com/bluetooth-trackers-android-samsung-galaxy-smarttag2-3539097/