>>11337382
>wake up in the morning to someone tapping on the glass
>it's Master!
>please don't kill me!
>pleasepleaseplease have mercy on Your slaves miserable life, please allow me to continue to serve you Master pleaseplease
>only been awake for 5 second and already ugly crying and begging for her life
>life is good

I think there might be some ventilation issues in there or something, she might suffocate for real. That'd why you maybe start off with tests of being forced in there for a few hours at a time, maybe have one of her sisters kneel infront of it while not being allowed to sleep just to keep an eye on her the first time overnight.

If she's having problems at like 3 AM she can always scream very, very loudly anyways. I'll come rescue her eventually. And deal with her in the morning.