I'm a middle child and my younger sister is completely insufferable at times. But if you actually take the time to hang out with your younger sibling and treat them well and show be patient with them it helps out. I had to sit down with my sister and tell her to stop being a ***** to me for no reason and asked her why, and that helped a lot actually. so try that. but don't be rude about it or blame her and judge her. Cuz yeah, big brother role is an important role eventually. sometimes wish mine was more a part of my life.