Malfoy and She-Potter

The story takes place after the battle of Hogwarts.
After Lucius Malfoy gets thrown to Azkaban , Narcissa changed her last name to Black and she also took Draco to move to 21 Grimmauld Place with her cousin Sirius Black. After Narcissa saved Harry in the forest, he understood where she came from and in insisted her to live with them.
Harry also had a secret twin whom Sirius and Severus knew about.
Hayley Potter was also part of the prophecy and she too fought the war alongside the golden trio and killed moldy pants with her brother Harry. But what happens when she meets her brothers arch enemy Draco Malfoy?