HELP! sleep question

My daughters will be one in a couple of weeks and one of the girls started screaming when we put her down. I mean she screams bloody murder. Before this started we would lay them down and they would not make a peep and go right to sleep. Could she be afraid of dark already. Has anyone had this issue? We even had her checked by Dr to make sure nothing was wrong.

 

Is it possible she is not tired and you need to adjust sleep schedule? We had to make the switch from 2 naps to 1 nap not long after a year old, and before that they started really fighting going down for naps.

 

One of my girls started doing this too a few weeks before her first birthday... I just continued with the same routine and there was only one night where she had a complete melt down when the only way she would go to sleep was for me to hop into my bed with her and she was asleep in seconds but this is very rare and almost non-existent for me to do this. Anyway.. my point being I think that it is really just a developmental thing and you just need to persevere with keeping to the same routine and letting her know that bedtime is bedtime.

She is still protest crying when we put her down but as soon as I am out of the door and downstairs, she stops and goes to sleep.