We are, in a queen, with a 2 month old and 2 year old!
I discovered early on that in those first few weeks of night-time diaper changes, it was easier to be in another room. The first night we were home from the hospital, we all slept in the same (king) bed, and the baby woke the toddler so DH quieted the toddler, and the baby and I exited to a queen in the guest room. I kept wanting to try it again, but was afraid that would happen again and too sleep-deprived to risk it!
We stayed with that plan til the baby was 5 weeks old (I nursed the toddler to sleep in their bed, then DH joined her when he was ready to go to bed. She had been sleeping through the night, not waking to nurse, since I was 3 months pregnant, her own doing, very nice
Now we're visiting the in-laws for a month so we have a queen bed and a queen mattress on the floor. Still me&baby, DH&toddler, but I SO miss sleeping with and snuggling my DD! This last week, we squeezed all 4 of us into one queen 'cause I just couldn't stand for us to be separate anymore. Works amazingly well - all sleep great!