honestly? wait.
I'm the oldest of three. there are three years between the eldest of my two sisters and me. we get along great and always have because those three years gave just enough time so ensure that we never had anything to fight over.
however, there's 10 years between my youngest sister and I. There's a definite generation gap there. While I'm a Gen-X'er, she's definitely not and at times it's very difficult to relate to her.