Draco Malfoy's soulmate and the Secret Sibbling

There was something that Dumbledore had failed to tell Harry that would've made his life happier, but he has a sibling he never knew he had, a twin sister named Hazel Potter. Why did Dumbledore lie to him when he asked for anymore family relatives?

But also why does Draco Bloody Malfoy keeps staring at her, why does Hazel use sign language rather than talk? Who has she been living with all this time and where has she been?

Hazel Potter is a transfer to Hogwarts after finding out who she really is, she can't wait to meet her twin again. she has always felt like there was a part of her that was missing, now she knows why. But who is the boy with the platinum blonde hair and blue eyes?
But also, why does Professor Dumbledore hates her?