Don't worry too much about the sleeping arrangements - even if your kids like having their own room. Siblings need closeness now especially. Sharing a room will help with that. You can always spin it as it being much cozier to share. My boys have a secret bed-time routine. I have no idea what they say to each other, but it is something special. These are memories they will have forever. Also, there is something at your pad, that your WW will never be able to match - you!
