A mudblood in Slytherin house?!

Kathryn thomas was of rich french descent raised in england and always felt like an outcast to begin with and she grew up down the street from harry potter who she despise greatly and knew nothing of magic being a muggleborn until like potter she got her letter of acceptance from hogwarts her parents where just as confused as her but what happens when a mudblood gets sorted into Slytherin house since year one the Slytherins have bullied her and mostly the richest pureblood of them all draco malfoy but when they start their fifth year at hogwarts it seems something has changed follow the story to learn how