My kids started room sharing at those ages exactly. Younger DS was sleeping through the night. We put him to bed first, then DD once he was sound asleep. There have been a few hiccups but they're now 2 and almost 5 and really seem happier together than apart. They go the bed at the same time now that DD doesn't nap.

It’s time for my 9 month old to share a room with the 3 year old. So far it’s a disaster. How long is it going to take to sort itself out.