Irene Adler learns the lesson early; beauty is power.
Beauty will get her what she wants, whether it's a new doll even though it's not her birthday or a lesser punishment when she breaks her mother's favorite vase. People are inclined to think better of the beautiful, and though she knows it's not fair, it's the one thing in her life that's not fair in herfavor.
Though she can't afford to go to University, there are few professors who refuse a beautiful young woman when she asks to sit in on their classes.
Knowledge, Irene knows, is also power.