We made the move from cot to big bed at the weekend and a couple of nights ago Charlotte realised that she could actually get out of the bed and come into our bedroom. As it was nearly get up time, it wasn't really an issue, but the next night, I closed her bedroom door and our bedroom door. Last night she managed to open her door, but couldn't do ours and knocked on the door (this was about 5 am), I'm sorry to say that as DH is away at the moment, I was too shattered to deal with taking her back and then her getting up again and again, so I took her back to bed with me (bad I know). But, she was told tonight before I tucked her in, that she has to stay there all night and that she can't come into my bed tonight.
If she does get up, then she'll go back into her bed. If things don't improve over the weekend, i'll look at moving the stair gate so that its across her bedroom door, that way, she can't wander about and hopefully will get the message to settle herself back down again in her bed.
Let us know how you get along.
Rachel xx