We moved Jovie into a room with Matilda when she was 9 months old. What we did was put Jovie to bed there, and then Matilda later. When Jovie woke up she would come into our bed, sometimes it was 1am etc... but at least we had a few hours by ourselves first Thats the way it still works, the girls share a room but if one wakes up they come into our room for a cuddle or whatever and generally go back to sleep in our bed. We have a spare mattress on the ground if they need it.