oooh headcannons for being Sirius Black's niece and moving into Grimmauld Place with him?
sirius’ niece...as regulus’ daughter? because what a concept!
regulus kept your muggleborn mother’s pregnancy a secret from his family, including his brother but before he died, he entrusted kreacher with a letter to give to you, entrusting the house to you, once you were born and it felt safe to do so. kreacher did so after hearing your mother’s name among the list of missing muggleborns after grimmauld place becomes the headquarters for the order of the phoniex.
sirius had no idea you existed until you showed up in his house and upset his mother’s portrait, who cursed you for taunting her with her son’s face. it was safe to say that both of you were surprised - you that the notorious sirius black was your uncle and sirius that he had a niece at all.
he’s absolutely delighted to have found you, seeing it as a chance to finally make peace with his brother and he can’t help but find your halfblood status a little amusing, given his family’s general stance on mixing with non-purebloods. when other members of the order raise suspicion about you, sirius is quick to remind them that this house is your birthright, just as much as it is his.
he cleans up regulus’ old room for you, which he’d been avoiding out of guilt and helps you redecorate it a little. the two of you leave up a picture of your father in his quidditch uniform.
having to explain to you that your father died a death eater ends up being one of the hardest things sirius had ever had to do. especially when you go completely silent for a couple of days afterwards.
when you and harry finally meet, sirius couldn’t help but smile sadly because all he could see were james and regulus’ faces.
you and remus get along swimmingly (after the initial shock that your old defense against the dark arts professor was close with your wrongfully convicted uncle).
