Acorna series

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 grizzled prospectors found her drifting in an escape pod amid the asteroids, adopted her, and took her to the bandit planet Kezdet, a place where no questions are asked and the girl might grow up free.

But Kezdet has its own dark secret. The prosperity of the planet is based on a hideous trade in child slave labor, administered by "The Piper" -- a mystery man with special plans for Acorna and her powers. But free little girls have a way of growing into freedom-loving young women, and Acorna has special plans all her own. . .

But Acorna has strange dreams of a gentle folk who mind-speak by touching horns. With her "Uncle" Calum, one of the three grizzled asteroid prospectors who rescued, protected, and raised her, she sets off to find her people. No sooner does she leave than a mysterious craft appears, piloted by the Linyaari, a gentle race with telepathic powers.

The Linyaari are roaming the galaxy, spreading the alarm about the deadly Khleev--And searching for a beloved little girl they had given up for lost, long ago...