Our daughter is 18 months old and we're expecting #2 in 3 months. She's started to climb up on the side of her portable crib a bit and onto her highchair, etc, so I'm sure that scaling her crib rails is not far behind... besides which, in all honesty, we'd love to avoid having to get a second crib.

Our plan was to transition her from her crib onto a floor bed (twin sized mattress) and then eventually pop the mattress into a bed frame once she's old enough and has figured out how not to fall out! She doesn't particularly like going to bed, but generally sleeps well though the night once she's gotten over her initial fit about having to go to sleep in the first place. One thing I am a bit concerned about is that she tends to migrate around her crib quite a bit... not sure if it's just as she's falling asleep, or whether she does this all night, but she's never in the same spot in the morning.

Any advice on how to go about the transition? Experiences with it from anybody who has already gone through this?