WHAT HAPPENED???

This morning Grace woke up as my baby and then she went down for her nap as my big girl...

After lunch I cleaned up, changed diapers, and told Grace to get her bunny and paci for night night. As I followed her to her room she pointed to her new big girl room. Just to play around with her I let her get in the big bed. I turned off her lights, closed blinds and went to leave the room. Thinking that she would then call my name and want me to come back and pick her up, but as I turned around she told me night night. I left the room and watched through the cracked door. She played and looked around for a few minutes then laid down, within ten minutes she was asleep. In ten minutes she became my big girl. I am not ready. I was thinking a few more weeks or at the beginning of the year, there is no bed rails, no monitor. How did she know it was time? How did she know that is where she was suppose to now lay her head? What happened???