DH, DD(23 months at the time) and I did all sit in one row. It wasn't easy, DH is "Pooh-sized" and DD kept trying to grab the drinks with the electric ice cubes of the people behind us (who we didn't know) and tapping on the people in front of us (who we were with.
i would think you'd have room in he "row " but like the other poster said there is very little room between rows so expect to be cozy with those behind you ! most little ones wouldn't sit still for as long as it may take to get your food there( we waited an hr for soup and burger)