Our daughters are five and going on three. We got a bunk bed and since about 6 weeks they are not just sharing a bunk bed but also sharing a room. It has been a positive experience in the sense that both of them sleep more calmer, wake up less often.
However, when we put them to bed. Our youngest (she did this before as well in her own room) starts babbling, singing, etc. Our oldest just went to sleep when she was alone in her room. Now, there are some quarrels between the two as our youngest is babbling, getting out of bed and our oldest starts crying, gets annoyed by her sister. This results in them calling out for my husband and I several times after we put them to bed which can go on for between 10-40 minutes at its "worse".
Some nights are better, but then I *think* they are both exhausted and have no more energy :)
I would appreciate any guidance on your behalf; your help has been invaluable in the past to our family and we tremendously benefitted from it.