I think my mother should scold my sister at 10 PM tonight, saying, Tonight, you better not play on your phone and sleep early. Tomorrow, you need to wake up at 8 AM to prepare breakfast.

If tommorow morning , my sister still doesn't want to wake up, my mother should scold her again at 8 AM for at least 20 minutes.

Last night I asked you to sleep early. Why didn't you want to sleep early?
On the day after tommorow night at 10 PM, my mother should remind my sister to sleep early. There’s a high chance she will sleep early and wake up early to help my mother prepare breakfast.