I have a younger brother that is just over a year younger than me. Growing up we used to fight all the time, and he is still a little piece of crap. But we do not really fight any more. Its something that happens when one or both are teens. But there is always something you can do. it may sound really cheesy and inauthintic. But ask her whats up, hows school etc. And if all else fails take her to waffle house.