L.A.
Get a twin mattress and place it in the corner of the room. Put the fitted sheet on it and let her make a nest of toys, and blankets on there. Our daughter filled hers with books and her lovey , and her favorite blanket.
Get a gate, that she cannot climb out of and place it in her bedroom doorway.
During the day, talk about how at night, she needs to sty in her bed and in her room. all night.
At night do the night time routine, Ours was read about 3 books, quietly, not with any questions and just simple reading. Make sure the lights are low. When you finish turn on a quiet CD with music or with a story on it. Kiss her good night and tell her "it is time for sleep."
You are doing a good job of just silently walking her back.. It will take a few days and nights, for her to realize you are serious and will not back down.