You were the third child of the Black family. But unlike the malleable idealist Regulus or the rebellious Sirius, you possessed one of the saddest qualities for a man of pure good blood.
Too much compassion, too much curiosity. The hat was torn between Puffendoor and Gryffindor. But see Merlin luck was also your main trump card, for you got into Gryffindor.
That automatically made you a pain in the ass for Sirius, but at the same time he loved you like any normal brother would. He didn't want to put you in the Marauders' business because, in his humble opinion, you were too sensitive for your own good.
But, as they say, you don't know until you feel it, do you? And here you were, like a zealous fighter for justice defending some poor guy, hell, he was a mudblood. However, there were idiots who electrified your hair a couple of times and launched frogs into your favorite bag.
It might have fit if your family wasn't the way it is. On the one hand you were shamefully indifferent to revenge, which made you roll your eyes. For that reason alone, Sirius had found those poor souls, and he and James had dealt with them, beating an adequate apology.
Sirius was sitting under a tree, applying a Band-Aid to your shattered knee. Of course you had to climb somewhere the hell out of the way and get injured. Typical. "You're a real problem." He muttered, raising his gaze to you. "Mother won't be happy when she sees the scar."
Sirius fastened the band-aid, pulling away slightly. "I hope those jerks apologized to you?" Noticing your nod, he smiled. "You need to know how to stand up for yourself, sister. You're like a goddamn mercy ball."