My girls shared a queen size bed from DD2 being 2 yrs old until only a couple of months ago. They loved it. It started as being a novelty thing one night when we were doing renos and were all sort of camping out in one room but ended up being what they chose. They now have chosen to share a room each with their own beds but will still share a bed regularly (they each have a queen size so there's no space issues for them and a million toys). I would in the early days have been in there with both of them frequently.

We often end up the four of us in our bed in the morning now, and when this bub comes along I imagine that will make five. Baby will sleep next to me, away from DH, but the "big" girls will sleep in the middle of DH and me. Its going to be squishy making sure the baby has enough room that she's not rolling off the edge, but I can't imagine a better kind of squish