I'm so sorry that you had to experience this disappointing behavior from someone you thought was your friend. Think of it this way:
You didn't lose a friend... you had the good fortune of seeing someone's true nature in a situation that didn't cause you any great harm. She really solidified her weakness of character by acting as if nothing happened. Best to just let this relationship fade away.
In the words of our beloved Indydebi, "NEXT!"

Miss_Sweetstory...I agree with you. She didn't lose a friend, just a person impersonating a friend...a frenemie. Some people are experts at doing this.

Its best she kick her to the curb before she does some REAL damage to her life. Trust me on this one....I know what frenemies can do to your life.