She is old enough to understand discipline. I would tell her that this will no longer be tolerated and that starting Monday, the rules will change. Give her a 2 day window, give her two days to be told everyday, several times a day, that as of..... day....she will go to bed and stay in bed. Tell her that you don't care if she cries all night, she is going to stay in bed. Get one of those door knob locks and threaten to put it on. Tell her you will start with putting this on her knob and show her how it works, tell her to try it and see that she cannot get out. Tell her that now that she is 4 that you will start an entire new routine. She will get her jammies on, brush her teeth, and she can pick out a book each night. If she does not stay in bed, the next night she will go to bed 15 mins earlier to make up for the time she is wasting tonight. You can bargain with her by starting a system that will work for her...for example...you can have a jar on her dresser and each night she is good, you put a marble in it...once the jar is full, she can pick out a toy. Or, you can fill it with dimes, quarters, whatever you choose. Put that lock on her door knob and tell her that she is old enough to behave and go to bed like a big girl. Get down on her level, you and your husband, with no distractions, and tell her that her behavior is no longer going to be tolerated. You will start taking away her favorite toys, taking away play time with friends, etc...whatever it is that she loves. Then you have to hold strong to that. You may go through a locked door and screaming a few nights. My son screamed at his door and banged until midnight. It was horrible but by the 3rd night he went to bed and stayed in bed. Every morning I praised him and did something nice for him. You can have a treasure chest that she can choose a toy, candy, etc every morning if she goes to bed like a big girl. If she does not, she has to put a toy in it that YOU choose, or maybe put money in it You be strong, get on her level, show her you are serious, and this should really work. Do not lay down with her, we did that and it started a whole new habit that he could not fall asleep on his own. When he turned 4 we told him that since he is 4 now, the routine changes. Now we read him a book, turn off the light and kiss him goodnight and walk out. Good luck! W. M