I'd be about an inch or two shorter, have a significantly slimmer build (for some odd reason the hugeness genes in my family are male only), and I would have slightly more breasts (women in my family are flat-chested). I probably would have essentially the same interests given my parents, the places I grew up, and the friends I had, though I probably would have actually tried to become a good singer (I love singing, but no Junior High boy wants to join choir), and I might not be majoring in computer science (I barely even wanted to in the first place, so any disincentive that women get would have been enough to stop me from going that route).
I probably would be pretty homely looking, since I probably still wouldn't care about clothes or make-up. Maybe having a sisterly relationship with my sister would change that, but I doubt it, since my brother was always more concerned with looks than my sister anyway, and my brotherly relationship with him didn't change that.
Basically, I would be a tall, lanky, nerdy girl with little idea of how to dress herself. I'd bang me. Also I would have the singing voice of a fucking angel. FUCK YOU SIBLINGS, I CAN BE MUSICALLY TALENTED TOO! *cries*
EDIT: Actually, now that I think about it, I wonder if my relationship with my dad would have been really different if I were female. I guess I might actually wind up with a personality even more like my mom's, so more snark, a more goal oriented mindset, and I'd be even less social. I might still wind up liking computers, and I might be even more of a nerd. Odd.