Bed time routine

So my sister in law is living with me and I have also had a bed routine, lights out at 9. But since she has stayed she doesn't go to sleep till midnight!!! I have tried to tell her that we cant keep the light on and the TV but she still does it. Would it be rude if I told her that she cant watch her shows in the living room anymore? I dont want her to tell my husband or her mom that she cant do anything.

Btw my husband is in another country so he cant say anything to her about this situation