V.B.
I think that when a child turns about two it is for sure ok to move into a tot bed. However for example our case....our Eldest was about 20 months? when we decided to start putting him into a tot bed ( I was already preggie about 7 months along and realized soon after I would not be able to pick Morgan up to put into tot bed, after rpeat c section). I am not gonna sugar coat and say it was not easy...cause it was not. Morgan did not under stand about the bed and was now mobile to move about the room at night. I stuck to my guns, adding a baby gate to his bedroom door ( that way at night if he woke and did not hear..) After about a week, it started getting easier...
I would maybe put up tot bed, introduce tot to the bed, let them sit on it and stuff....then child proof the room ( again for anything 3 feet and under)
hope this was helpful