I was always aware of bub there too. With two co-sleepers (DS2 wasn't), we never, ever looked like rolling on either of them. I've always tended to lay on my side facing bub, or on my back (we're in a queen too). Initially DS3 as a tiny tacker would only settle if he layed on me, tummy to tummy (he had some colic issues). Then I'd gently transfer him between DH and I. But after a while we just placed him between us and he slept beautifully. He still prefers to sleep that way at almost 14 months, but it's kinda nice. I think the main thing is to not overheat him. He won't roll around much at this stage, so maybe have him as high up the bed as you can, but with enough space at his head that he won't end up in the bed head. I've also always moved my pillows as far away from bub as possible - generally half off the bed. DH used to take his off the bed entirely. That was really our main concern once DS1 and DS3 started rolling and being more mobile. I think as your confidence grows, you'll find your own groove and what works for you xx