vero, try to think of your sister and brother as using terms of endearment when they call you their little sister. it's a little like how our children will always be our "babies".
i don't think they're being disrespectful. quite the opposite. i think they're showing love for you.
the anger you feel about it might be because of insecurities.
i love my "little sister" so much, and she's 60!
M:63 H:53 S:41, SS:28, SS:25, SD:23 M:15 T:16
Bomb:12/17/11, "I think we should go our separate ways." H moves to his mother's house, 4/1/12 12/21/12: H moves back home, piecing