If children don't go to bed at the right time, and stay up too late, it's harder for them to fall asleep. Also, if you are with or near your child when they go to bed, it take longer for them to fall asleep. If she doesn't know how to fall asleep on her own, then that is a problem.
Whatever method you choose to do, stick to it, don't waver, keep a blank face. If you return her to bed, keep doing it and don't say a word to her and show her that you will not give up.Period. If she cries hystrerically, it will be over in a day, or two, or three. And then there will be peace. But, each successive day the hysterics will be shorter. DO NOT GIVE IN. Once you give in, it's worse than starting all over b/c she knows that enough of her crying will make you cave and it will be harder. I PROMISE, after a few days, she will stay in bed without crying and fall asleep on her own.