M.W.
Hi. I have a 1yr old and a 3 1/2 yr old both girls that share a room. It seems to work out OK. Although I do need to put one of them down first. Wait till they fall asleep and then bring in the other. Which is usually my youngest first. My oldest knows not to wake her sister if she gets up first, she will just come out of the room quietly but if they are both awake they will play. I can see that it may become a problem once they both get a little older, like say in another 2 years maybe, but for now it's OK. Good Luck!