Unattended access for 85 year old Grandma who want to learn to use the internet!

Hi,  I am not sure whether this is the place to ask my questions. My 85-year-old mother asked for a tablet to learn to use the internet. Since she lives alone in Texas and I live in Europe, being able to have full remote access to her tablet is a necessity.  I have figured out how to connect to her tablet but she would need to allow me to access after each time she turns off her tablet.  From what I understand, it is possible to set up "unattended access so that  I don't have to call to get mom to allow access each time.  But I have not figured I out the following questions:

1. Do I have to pay to have true unattained access and not how it is know that she has to approve access each time?
2. Do my computer and her tablet need to be signed in with the same email?
3. Do I understand correctly that my mom will be the "host"?
4. This morning when I tried to remote control my own tablet (which is similar to the one I got my mom) a big blue finger appears when I point to something, but I am unable to control my tablet.  I logged on to TeamViewer again to see if this resolved the problem.  I get a message that this device supports screen share only. I did not have this problem yesterday.  Have I caused this my self?  This is possible since I have "clicked around" to get to know how TeamViewer function.  I tried the reverse by connecting to my tablet to control my pc and all was fine.

Thanks,

Zaza