You've Got to be "kidding" me

I'm 19, not 9. I'm not little, I realize I am a little younger than most of the juniors, I am young for my school year, but who cares. I am tired of everyone always telling me I'm little. I'm not the little sister, or the youngster, or the "innocent" one insinuating I am a child. I'm not offended per-say I just don't appreciate being a junior in college and still having this title. I'm not a baby or a child. What makes me little? What makes me younger then them beside technically my age, but they are only a few months to a year older than me, not that big of a difference. How am I SO much younger to categorize me as being the little sister of the group? This isn't even a group, we are roommates, we are equals. Also, to say I party a lot is the most ridiculous thing I have ever heard. I do not party. Choir camp is when we do fun things for the freshman, I am out late because I am making sure they are all there, everyone has rides, everyone gets home ok, I drive the homesick and physically sick ones home, I stay out late when the girls need someone to talk to, I'm being the mom if anything, not being a crazy "kid" in college just partying it up. I study very hard, and I have worked my butt off to get to where I am today. My major is one of the toughest majors and if they don't see that then who cares, I know that I work hard. When I come home late sometimes it is because my shift doesn't even end until 11 and I'm lucky to get out of there at ten past 11. I might be studying with someone, but it is RARELY, and I do emphasize rarely, am I doing something just for pure enjoyment. It is just a bit frustrating. They don't even know me and already they have this view of me. It isn't a bad one and I should be grateful this is the one they do have because Lord knows it could be far worse, I just do not appreciate it is all.