First Book in the Adventures of the Unicorn Girl.
It had started as a pleasure-cruise spaceship, but as the Khlevii moved close to them it threatened to turn into a death chamber. They knew there was no hope for them, the adults, but they took a chance on their youngling, nestled into a pod and ejected into space before exploding themselves and the hated Khlevii with them.
It was three young space prospectors in an asteroid mining ship, the "Khedive" who hauled the piece of space debris aboard and opened it up. It contained an alien youngling, though of which sex was at first debatable. Silvery hair curled down over the should-blades and, in the centre of the forehead was the beginning of a small horn. The feet ended in tiny cleft hooves. The little alien was frightened, affectionate, and she was to become their mascot, their miracle girl.
Many people on many planets wanted her and the mysterious powers she possessed, but Acorna had her own ideas of the tasks she was to accomplish in the worlds of space.