From my understanding the aircraft had left the ground and 5 seconds afterwards the lady reclined her seat. If this is correct there is no reason why any seat should not be reclined. There is no signals from the Captain to say when you can now recline your seat. Having said that the the lady should have more considerate and reclined the seat more carefully. If you found the seat intrusive then you could have reclined your seat also. Everyone is entitled to recline there seats other than at takeoff or landing. The only time I would request a passenger to keep their seat upright is during the meal service and this would only be in W/T or E/T.
CIHY