Piebald is beyond outdated. Piebald only means black and white, whereas skewbald means white and any other color. Yes, technically, she would be a piebald, but that is very outdated.
She would be a black tobiano and splash. Tobiano is causing the majority of her markings: white crossing her back, particularly her neck and color on her chest and flank, etc.
Splash (which falls under the blanket term "overo") is causing the blue eye and her stripe that angles down to one side. Tobiano does not cause face white or blue eyes.