K.B.
My three brothers shared a room, (I was the only girl so I got a room to myself, lucky me!)... I know that mom would always introduce the baby into the bedroom when the baby was sleeping through the night, and I think it averaged around 6-7 months old. My brothers were about 2-3 years apart from each other, one was a deep sleeper the other one was a very light sleeper so the baby MUST be sleeping through the night if you have a light sleeper. Oh and if any of my brothers were in school (preschool on up and up) she waited to make the transition during the summer so they could get use to it and not have to worry about getting up for school and being tired from not sleeping well. I remember them always being loud at bedtime but a month after the transition the newness of it seemed to wear off and they would just go to sleep with little to no chatting.