Another planet

A girl named unicorn grows up with her best friend (teddy bear) and twin brother(tree bark). On a different planet that no human knows about until her best friend teddy bear brings a human back to maydupiter. When teddy bear brings the human back she has to hide her from everyone on the planet except for unicorn.
And if the girls friend brings a human back will she be hurt? Will there be a stoaway on their space ship or will she be killed on earth with her parents and cousin? Will the human be okay on the planet?