Your children sleep?

I started my kid on a full sized bed and called it a day. That will be big enough for her to share with a friend and/or cousin until she's an adult and out of my house. She slept wild in it at that age, but she sleeps mostly correctly in it now at 4. although dead in the center. Perhaps by 8 she'll have a favorite side and the answer won't be "why not both" lol

Mine both decided that the best way to learn to get out of their cot was to get their hips up against the side, all pressure on their arms and then tip forward headfirst onto the floor. In both cases a mad scramble for a toddler bed and teaching them to stay in their bed at <2 (a hopeless cause resulting in soft floors and a tall stair gate on the door) resulted

By three in both cases they were in full size singles for different reasons and so far there they stay (8 and 4 currently)

My 3 year old is in a toddler bed and she's fine even if she rolls into the sides. She isn't bothered by it. She sleeps mostly fine. Her crib converts into a toddler bed (current state) then a full size bed. It seems like a giant leap but I think she'll love the space... Not out of necessity but because it's fun.

My 21 month old is still in a crib (cot). He's 99th percentile for height and he's still comfortable. Rolling or turning up against the bars has never affected his sleep.