Who is Jaylin?

While on Earth, Krel has no interest in the planet's culture or humans for that matter, unlike his sister. Instead he focuses on doing whatever it takes to escape there before or the bounty hunters or general Morando capture Aja, him and Varvatos. One day in school he has to work with his invisible classmate Jaylin. After noticing how popular Aja had become in their high school, Krel
wanders, since they're gonna be there for a real while and he's stuck with her anyway, could this girl be a good friend?
Takes place between episode 7 and 8 of 3below.
Disclaimer: I don not own the show.
P.S. Cover drawn by me.