I have the A-13 and she owns an IPhone 11. I am not sure how that is possible, but I can't delete or edit the contact list because the edits syncs to her phone. I don't know how to fix this.
do you have your mother's account on your phone? I have my mother's Google account on my phone for a number of different reasons (she's 85). I turn off sync on her contacts so those don't annoy me in my Contacts and Phone app.
