As a fellow 5'4 girl, I wish you luck. I've not been in many mosh pits, but I've been in enough to know to just expect to get beat to shit. :P Back in my day I mostly used defensive techniques. I really can't give much better advice, it's been a while since I've been to a show with an actual pit instead of people just shoving to get closer to the stage EVEN THOUGH THERE ARE ALREADY PEOPLE STANDING THERE. /rant