Supergirl (idk who yet) x fem shy...

Marine mammal behaviorist, Y/N, doesn't really have friends, she's very shy around others. That is, until she meets Alex and Kara. The DEO is tipped off about an unknown person as the target of something bad. Who is this person and why are they wanted so bad? Y/N has been acting strange as well, for she has a dark secret. How long until someone finds out and how will they react? I know, this is a crap description. I'll probably add something to my message board asking for any suggestions for a description or something idk. Anyways, enjoy!