Your daughter has developed a fear of choking on solid food after that traumatic experience. You can try to help her get over it by discussing the pros and cons of this fear. She is old enough to understand. Try to arrive at a mutual understanding how she can overcome this fear by taking gradual steps. She can try with semi-solids, then move to small bites of solids. Encourage and praise her small steps to normalcy. In case the fear persists, you should consult a psychologist for assessment, counselling and intervention.