Most people can answer this question easily: What is your gender? Haillie answers that question depending on what day it is.
She could be a very pretty girl when she wanted to be. She had short spiky blonde hair, usually with red tips. No matter what gender she felt like being that day, she always gelled her hair up to stand straight up in spikes.
Haillie was born with both male and female parts. This is why she chooses which gender she wants to be depending on her mood.