This is the official site for Annica: Starseed Ambassador, a novella by Greg McClanahan.

These are the locations where it is officially available:

Synposis: Fourteen-year-old Annica hadn't given much thought to the possible existence of interdimensional aliens, until the day they recruited her as their future ambassador to humanity. With her worldview in shambles and her mental health under heavy strain, the high school freshman struggles to separate the real from the unreal while preparing to realize her extraordinary higher purpose.

Reach the author at (please include "Annica" in the subject line).