Margaret Ball and Anne McCaffrey: Acorna

She was just a little girl, with a tiny horn in the center of her forehead, funny-looking feet, beautiful silver hair, and several curious powers: the ability to purify air and water, make plants grow, and heal scars and broken bones. A trio of mining prospectors found her drifting in an escape pod among the asteroids, adopted her and - when that adoption was questioned by the authorities who wanted to experiment on this strange girl - fled with her to the bandit planet of Kezdet, where nobody ever asked any questions.