My daughter recently turned three. This means my life is full of Disney Princesses. We have the dresses, we watch the movies, we listen to the songs in the car. I'm just praying she never finds out that Disney World is a real place. While the Princess hierachy is always in flux, Cinderella is usually in the top three.
Now we're all familiar with the Cinderella story, but I'll rehash. A kind-hearted young woman is mistreated by her wicked step-mother and two horrible step-sisters. With the help of her Fairy Godmother, Cinderella dons a beautiful dress and rides in a pumpkin-turned-carriage to Prince Charming's ball where they fall in love. Before the prince can ask her name the clock strikes midnight, and Cinderalla runs away before her magical ball attire disappears. Providentially, Cinderalla loses one of her glass slippers. Prince Charming declares he will marry whomever the shoe fits. So the Grand Duke sets off across the kingdom, slipper in hand, to make young maidens try it on. The wicked step-mother breaks the slipper before Cinderalla can try it on and prove that she is the Prince's true love. Cinderella is seemingly prepared for this situation by presenting the other glass slipper, and they live happily ever after.
No, the real flaw is Prince Charming's plan. He's going to marry anyone that the shoe fits. I mean sure, it would be great as some form of early filtering criteria, but it can't be the deciding factor. The chances of finding Cinderella with this method are close to zero. How close to zero? Let's find out.