Nine year olds are growing children. You're daughter may be going through a growths spurge in which some eat a lot and others don't. If she's hungry, she will eat. If she's not, you cannot force feed her. That will make her resent you more. Give her her space but let her know that she isn't getting anything until breakfast time because she can't be getting up in the middle of the night. You shouldn't make her sit there. You're wasting your time and energy when you could be spending quality time with her at night.
Responses are not reasonable. Everyone not hungry at all times. Bodily needs ever changing. As a parent you must make loving judgements. Punishments over food and eating set up life long eating problems. Would suggest some research on the subject of getting a child to eat.
forcing her to sit until she is done only does one thing- create a conflict of wills. let it go. creating a battle ground over a meal is only going to cause more issues later on. know when it is important to assert your authority, and when it is best to just say oh well, she is a child.
I would always fell asleep. I used to tell my kids I you can eat it all then you have to eat "this" much, an if they didnt then they had a time out for a little bit and no snacks. It wasn't worth te fighting over forcing them to eat.
Making her sit there is a war of "wills" who's going to win, not you! Simply take the food away and nothing until next meal. However you can try a few things, if she doesn't eat she must leave table and go to bed lights off no entertainment, the second thing is a rule, take all you want, but eat all you take. Another rule try two bites of what you don't like and you can leave the rest.
You could always talk with your PCP which is also known as primary care physician/ family doctor. Explain to the Dr. that she is not eating and see what they suggest doing. It may be she is not hungry, growths spurt or anything. But you should make sure that that's all it is.
Why not just have her sit at the table with you for a reasonable time during meals, if she doesn't eat, fine. No snacks or treats until the next meal is served. Or at least an apple or yogurt, but no junk food. When she's hungry she'll eat. As it is, it's turning into a battle of wills. And she's winning by proving she is NOT going to eat. Why not make it a nonissue?