One thing to keep in mind is that she can probably sense your emotions, so you should try to stay as stress-free about it as possible. If you are nervous or uptight about school, she will be also. If she hasn't spent a lot of time away from you, she will likely cry when you leave her. This is usually for your benefit to get you to stay, so you have to reassure her that everything is going to be fine and that school is going to be fun. Don't let her see you upset (I am assuming that the first day will be emotional for you, but try not to let her see you crying). Once you get her settled, try to leave as quickly as possible after a hug and a kiss with a big smile on your face. If she sees that you are excited about it, then she will be less likely to get upset. If she does cry, the people that work there will expect that, so just leave quickly and let them soothe her. In most cases, they stop within a minute or two when they can re-direct their attention to something else. You know that this is the best thing for her or you wouldn't be putting her in school, so you just have to trust that the teachers will take over and after a week or two, she won't even think twice about it. Good luck! Leaving our babies is hard, but they need that time with other kids too, so you're doing the right thing!