Heather Cassiopeia Black was the daughter of Regulus Black, brother of Sirius Black and Daisy Lupin, sister of Remus Lupin. She was left at the gates of her uncles when she was merely 6 months old. So they took her in as their own. Then Lily and James died, Harry was taken away, Sirius was put in azkaban, Peter died and she was almost torn away from the only person she had left in the world.