Tough situation for OP. Been there before with 2 kids and wife all booked in first class and they still managed to bungle the seating. What's even more concerning is how unwilling fellow passengers are to swap seats for the kid's sake. In above scenario, I am sure a stranger could have ended up getting an aisle for window swap and at least put the two oldest kids together. I have found basic courtesy to be dead in most public transports these days. Go ride any subway or city bus and see how often young healthy men get up and offer their seats to the elderly, pregnant, etc. It never happens. What's worse is it ends up making you feel like a fool for doing so.