At the beginning of December we decided to put Mason and Lily together in the same room since squishy is going to be born soon. The transition went fairly well. I think the biggest reason it works is because they are on different levels and even though they can hear each other they aren't right by each other all the time. We bought Lily a twin bed instead of using the toddler bed because we wanted to avoid another transition. She looks so cute and tiny on the bed :) And of course I love that she loves her elephant lovey so much!!!
Here are a couple of Mason, I think that first picture is funny because he sucks on his tounge still when he sleeps. He has don't that ever since we got rid of the binky, haha. And in the second you can see his silky is close at hand :)