Snopes: Debunking propaganda since 1995
So, rather than presenting three images of the same girl (in the same clothing) supposedly being carried by rescuers after three different "refugee crises" in separate times and places, this triptych simply captures one girl being passed around from one rescuer, caretaker, or family member to another in the same disaster zone as part of humanitarian efforts undertaken after the same single bombing event in Syria that left 16 people dead. We found no evidence that CNN ever used any of these photographs to represent anything other than that one event.
A variation on the ‘crisis actor’ conspiracy theory holds that CNN used photographs of the same girl to represent three different refugee crises.