I had tilly in a cot until well over three, even close to 4 years. She once "slept climbed" out but never again. She slept well in it and then was totally ready for a bed and we didn't need a rail as she' was almost 4. I will do the same again if coco allows it. I know both my goddaughter (2 ) and nephew nearly 3 were both moved to bed at 2 and neither will stay in it, sounds like a nightmare to me! oxoxo