My wife has booked a flight back from SIN to JFK. She is traveling with our 1 y.o. This is her second long haul to the region. Wife ha to work the next day after landing and wants the comfort. The infant lap child fees are over $1000. We may be able to book her sister in coach on the same flight and tag our daughter to her PNR instead. If we did that, would the FA's allow our daughter to sit with my wife in F for parts of the flight? I am thinking it is ok up until if she makes noise. At that time the FA's may kick her out. So do we pay the $1000 or roll the dice?