It does take a while for them to get used to not wandering, because at the start it is a big novelty for them to get in and out in and out. So at first I would close their bedroom door and they would eventually go to sleep and if they were on the floor I'd put them into bed then. Because Paige was a bit younger, to get her used to it I would put her in her cot to go to sleep and then put her in the bed. As for night wandering, they rarely do it. Most of the time they will stay in bed and call out.

Or you could leave it until you move and make a big fuss about her new room and her new big girl bed. I don't think 3 would be too old either. Can you take the side off the cot in preparation for the bed and see how she copes with that?