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She won't need a convertor, but she'll need an adaptor. The convertor changes the plug shape and voltage, but the adaptor changes just the shape. The iPhone plug can manage the voltage, as it is rated from 100V-240V.
 
The iPhone charger will be fine as it is two prong. For 3 prong chargers such as laptops, should have an adapter handy just in case.
 
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