Zak Storm's Sister

I don't know what to call this, but if anyone has any name suggestions for this book, then please comment them! Based on a couple votes I received on my announcement, my OC name is Rosa Storm.

Rosa is Zak's 16-year-old sister. Her and Zak constantly fight and argue back and fourth, and when Zak and his crew finds her on the Chaos, nothing changes.
Until one day when Golden Bones arrives in the hope of bringing Zak to Skullivar. Will Rosa pause their battle long enough to save him, or will she just let Skullivar do whatever he wants?