Isn't it risky to send a child (person under 18 years) through airports with complex connections? Regardless of how travel savvy the child is, and regardless of how safe the airports are from crime, all it takes is one encounter where a police officers ask for ID to turn this solo trip into a catastrophe costing you thousands of dollars and days of time to fix. BTW, that encounter could happen very innocently when a concerned traveler or airport employee tells a police officer, "I see a child sleeping in the airport 'abandoned' by her parents."