Children sharing a room

Kaitlyn

So i have a 3br and 2 kids a 5 year old boy and a 1 year old daughter. I have my 3rd on the way. I was thinking of putting our baby boy once old enough in the same room as the youngest. When would u put the baby in the same room as the youngest and what would u use for the baby to sleep in the same room as u in the mean time??