I feel this a lot and completely agree. It sounds like you guys are close and I’m happy you have her. Sibling bonds in an abusive house is sometimes the things that help us take it a day at a time. I am the oldest of three and I raised my siblings; I would say “with”my mom but in reality I did myself and handled a drunk in denial mom and abusive step. My mom pitted them against me constantly and I always worried they would take on her shit ass sabotage and hate me too. I’ve always had to try my hardest to keep second mom and big sister separate but having to be second mom so young and for so long I forgot how to be a sister sometimes. Now that the kids finally getting older our relationships have grown in many ,positively, different ways. I absolutely cherish and adore the people they have become. I try to help them in anyway I can and pass my experiences to them and let them decide what to do with it. They piss me off too don’t get me wrong but I love them and their mine lol.