How to close access to individual wifi users?

Question

Android

I have a sister, she sits constantly at her phone, and she sits only because of the Internet, and she sits through wifi. And I need to make it so that she could not sit through my wifi. In general, I’m sitting through the wire at the computer, my sister and dad are sitting at wifi, and I just need to block my sister’s access, is it even possible to do this?
PS I apologize for the tags, I didn't know where to put it.

Answer 1

Filter by mac

Answer 2

You can set it to low priority if the router supports . Why completely block when there is nothing worse than slow internet. (wiping away)