I am not an employee or crew of any airline but I know that I have to obey crew instructions when flying. This includes staying in one's seat when the Seatbelt sign is on; no matter the conditions. If this woman had been allowed to ignore the Seatbelt sign; sustain an injury then she would be suing the airline. The captain doesn't turn on the Seatbelt sign for fun but for safety.

If you have a physical condition that may affect your flying, then take precautions but once on board a plane, the crew is the law whether one likes it or not. Seatbelt sign on = stay in your seat with the seatbelt fastened. This woman might want to invest in wearing adult incontinence garments on flights but blaming the airline for not allowing you to violate the rules don't cut it.