We have always co-slept with our two babies, the first until 12 months old, the second (14 months) is still in with us. At 1, we moved our oldest DC into her own bedroom without any problems and she slept on a mattress on the floor (her choice). She now at 3.3 years sleeps on a double bed which happened to have always been in her bedroom, from before we had her. She is happy in her double bed, never falls off etc.
We are thinking of moving DC2 into that bedroom shortly and I am wondering if they can both sleep in the double? They are used to sleeping with each other, as DC1 often sneaks back into our bed, so there are four of us sharing most nights. I don't think DC2 will fall out, as she is used to sleeping in our double bed, alone between the hours of 8pm - midnight when we go to bed.
Am I missing something? Will it be ok for them to share a double bed? I know they will be happy to do so but from a safety / other perspective?