The App isnt linked to your mobile number .. i can access app on Ipad and mobile at same time so I struggle with that .. I will try with wife’s phone tonight as a test!
If they are really family you trust surely you just sign them in as you on their phone? Give them your login and password and they are you for the day? If you dont 100% trust someone thats different.. but what am I missing? You wouldnt even need...