I agree, it's either a sneeze or a cough. Sometimes they get a bit of feed or something in the airway, and that happens. See if it resolves on it's own. Some birds will do it when they eat or drink. If it persists and gets worse, or she has any discharge from eyes, nares or beak, any bubbles in the eye, etc. then it would mean a respiratory illness. She appears to be pretty healthy in the video, so likely just something temporary.