Does my character sound like a Mary Sue?

Her name is Lacey. She ran away from her home after her mom married an abusive man. At night, she tucks her hair under her hat, puts on her mask so nobody will recognize her, and plays her violin for small tips anywhere she can. Because of this, she becomes known to the area as the “Masked Violinist” who nobody really knows. Nobody even knows if this “Masked Violinist” is a boy or girl, but everyone assumes the Masked Violinist is a boy. She knows this, but she doesn’t mind much because she thinks that if she were a boy then her step father wouldn’t have hurt her. She luckily gets taken in by a family of four that includes a mother, father, son, and daughter and they enroll her in the school, and everyone pretty much guesses that she’s a runaway. Whenever anyone asks her about it, though, she glares at them and chews them out.

That's basically all I can say without spoiling the story…. I've taken numerous Mary Sue tests and she always scored low Sue-points, but I just want to make a double check with REAL people... ^-^; So please be COMPLETELY honest with me here. And if you want to know what she looks like I’ve put a drawing of her below ^_^