On a recent flight with Club Suites there was a family with 2 young children and they were sat behind each other in window seats. The parents were having a real issue getting the youngest child to stay in their seat for take-off (they were maybe 2 or 3) - the mother kept having to get up as we were taxiing to try and get her to sit down and it all seemed rather stressful. I will caveat that with the fact that we had a one hour delay after pushback, which can't have helped the situation. Middle seats or 2 rows across the aisle from each other would certainly be a better bet than four in a line, but it's really not an ideal set up.