DD1 and DD2 share a room. DD1 asked for them to share. There is a 3.5 year age gap. We haven't had any issues. DD2 has lots of rough nights and she doesn't wake DD1. If DD2 wakes early, I often hear DD1 chatting to her so she doesn't cry. It's very sweet. We often ask DD1 if she wants her own bedroom again and the answer is always no.