J.M.
J C,
My MIL is a mother of five and always suggested leaving the kids in their cribs until they started to climb out or protested going into their cribs. I did this with both my children and found the transition to be minimal. My girls made the choice of going into bigger beds. It was not a forced situation therefore it went very easily. The biggest difference I found was getting them used to the idea that once they were in bed they were not allowed out of bed. They thought it was OK to play with a few toys once I left the room! A few days of correcting them each time they got out of bed did the trick. I sometimes give them a flashlight and books if they are having trouble getting to sleep. Other than that it was a piece of cake.
Hope this helps & good luck!
Jen