I'd like to take this opportunity to quote the original story as written by the Grimm brothers:
The next morning, he went with it to the man, and said to him, "No one shall be my wife except for the one whose foot fits this golden shoe."
The two sisters were happy to hear this, for they had pretty feet. With her mother standing by, the older one took the shoe into her bedroom to try it on. She could not get her big toe into it, for the shoe was too small for her. Then her mother gave her a knife and said, "Cut off your toe. When you are queen you will no longer have to go on foot."
The girl cut off her toe, forced her foot into the shoe, swallowed the pain, and went out to the prince. He took her on his horse as his bride and rode away with her. However, they had to ride past the grave, and there, on the hazel tree, sat the two pigeons, crying out:
Rook di goo, rook di goo! There's blood in the shoe. The shoe is too tight, This bride is not right!
Then he looked at her foot and saw how the blood was running from it. He turned his horse around and took the false bride home again, saying that she was not the right one, and that the other sister should try on the shoe. She went into her bedroom, and got her toes into the shoe all right, but her heel was too large.
Then her mother gave her a knife, and said, "Cut a piece off your heel. When you are queen you will no longer have to go on foot."
The girl cut a piece off her heel, forced her foot into the shoe, swallowed the pain, and went out to the prince. He took her on his horse as his bride and rode away with her. When they passed the hazel tree, the two pigeons were sitting in it, and they cried out:
Rook di goo, rook di goo! There's blood in the shoe. The shoe is too tight, This bride is not right!
He looked down at her foot and saw how the blood was running out of her shoe, and how it had stained her white stocking all red. Then he turned his horse around and took the false bride home again.