When your sister asks you to watch her kids, all you need to do is put them in front of the tablets -- problem solved! (I'm joking of course)
I remember the days when I used to fight with my siblings over which channel to watch. Kids nowadays each have their own tablet/phone, can watch any show they want on demand. When their parents tell them to go to bed, they can pause their show and resume under the blanket in their bed! They have it so easy and don't even know it!