Emotion-dependent ability, drifter..
Julianne discovered at a very young age that she had a special ability. Some would see it as a gift, others would look at as a curse. Her parents knew early on that there was something different about Juli. It was discovered that she had two powers that were linked to her emotional state. Different emotions triggered different abilities. For example, intense anger will give her more violent or destructive abilities (strength), while fear or desperation would allow her to use powers to help her escape the situation (invisibility).
Juli's parents tried desperately to keep their daughter's power a secret, punishing her whenever her abilities were used. But of course, you can't control your emotions. And it seemed the harder Juli tried to hold it all in, the more emotion she began to build up inside. Afraid that they had lost control, her parents kicked her out of the house when she was sixteen years old, in fear of their own daughter. She was forced out onto the streets and did whatever she could to get by which including stealing and doing miscellaneous jobs for some not so good men. But she was just trying to stay alive..
In the midst of all her trouble, Juli was finally starting to fit in somewhere, and found friends. She was finally starting to feel happy again, and didn't want to have to keep lying to them every time she 'disappeared'. So she revealed the truth about herself to her new friends, and they did not take it well. In fact, she vaguely remembers them calling her a 'freak', and telling her to never come back. The even threatened to reveal her secret to the world if she didn't stay away from them. So, it seemed Juli was back to square one in regard to finding a place to fit in again. She's heard rumors of a place especially for people with unique abilities. After some more research, she was recruited and enrolled into the Academy as a new student, hopefully where she can learn more about her powers, and how to control them.