Queen Rania of Jordan - with her modern outlook and postings on the internet she has a huge following of women and men in the middle east and is very influential. Mrs. Merkel, the German Chancellor has a tough and powerful job and a huge responsibility with Germany's economy and their trade around the world.
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Hillary Clinton, Sonia Gandhi & Indra Nooyi are said to be some of the most powerful ladies in the world. But the most powerful lady be one only. I think Hillary Clinton is the most powerful lady at the moment considering the American power she has more power than any other lady in the world!!