Slythindor Fondness

Delilah Ana Malfoy the oldest sister of Draco Malfoy. She is not like her family. She hates Voldemort, she hates her father. She wants to protect her family from Voldemort.
Twiwizard Tournament is happening, and she doesn't want to be at home. She decides to go to Hogwarts. Luckily for Delilah, Dumbledore allows her to teach Muggle Studies. She loves muggles and knows everything about them.
Bill comes since his helping out around the place with Charlie. Bill does not trust Delilah that easily but decides to keep an eye on her.
When everything is going weird, they bond over the fact their the eldest and that they have to protect siblings.
Delilah had a crush on Bill since her first year in Hogwarts but of course a Weasley will never love or marry a Malfoy.
Will they fall in love or just stay friends?

Will take place in Goblet of Fire, Order of Pheonix, Half-Blood Prince and Deathly Hallows in Acts.