Falling Asleep

The night before last Summer was really tired and it was early so we brought her into our bed but after a few minutes she wanted to get up and play so Papa took her upstairs to her room. After a long time of playing it was finally bed time. I had to go to the bathroom and figured when I was finished Summer would be back downstairs in our bed to settle herself down before going to sleep. I came out to find she never came back down, Papa was able to put Summer right in her crib, awake, where she fell right asleep. I was very sad. Last night we were in bed watching Sesame Street and Summer was ready for bed. She was hugging on her daddy, who takes her up when it is time, and when he asked her if she wanted to go to bed she put out her arms to be carried up to her crib. I was once again very sad. How come she wants to go to her crib to go to sleep, why doesn't she want to stay with us in our bed and fall asleep? I thought it was going to be much harder to break her of the habit of falling asleep with us in our bed but apparently not and I am not really happy about it. Does anyone know how I can reverse this horrible new development?