I sent a message to the girl at 9 pm, but the girl didn't reply. Is it possible that she is asleep? How to judge?

You send a message, she will have time to record. Otherwise, she will fall asleep, because girls are more gossipy. If she has a good relationship with you, she will praise or leave a message at the first time. If she doesn't, she must be sleepy and asleep. Of course, it is also possible that she didn't sleep, didn't want to reply to your message, didn't want to talk to you, and didn't open what you said, so there is no way to know if she slept, but she usually can't sleep at nine o'clock. Nowadays, young students can't wait to stay up until two or three o'clock, and their hair falls off, so they are all bald, so there is a great possibility of waking up. You still don't want her to fall asleep, it's just psychological comfort!

Present situation of staying up late and losing hair