I have a younger sister and I understand the feeling quite well. Brothers and sisters are still under one roof and occupy the same room, right? Indeed, they can be very annoying.
However, don't worry about it. They're in fact just aspects of development. They may pester, interrupt, or be rude, but it is all in search of Self, forlorn moans at midnight when they're alone - or another way to manifest love and sympathy. Don't fly off the handle but try to see things from their position.