The Brave Slytherin

Y/N Potter is a girl in Slytherin, but not just any girl. She's a girl with a secret. Nobody in her family knows that she's a Slytherin. Everybody, except her brother Harry, thinks she's a Gryffindor. How will her friends react when they find out that she hides her Slytherin-self the moment she steps off of the Hogwar...