DD1 moved into a bed at 3yrs but was in a Boori cot with the sides off from about 2 yrs. We knew she was ready for the sides to be off when she climbed out of her cot onto the change table next to it and i found her sitting on the change table pulling out baby wipes and throwing them around like confetti.:-0

DD2 moved into a big bed at 16 months. She was screaming every time i put her into her cot but settled herself if she was in a normal bed (mine or the spare room). Just a determined little one who thinks she can keep up with her older sister.

They both let us know in their own way that they were ready themselves.