It's probably Black Siren, but this still makes no sense. Why would they not lock her up? And I hope Prometheus didn't go in and break her out because that would be really contrived.
If it really is the real Laurel they better have a damn good reason for her being alive.

I think we'll find out in one episode or two, they won't drag this very long.

That was dumb and the writers forgot all about that.

Remember if it's Black Siren she'll be left handed if Earth 1 Laurel was right handed . If she's from Earth 2 she'll be bound to slip up her dominant hand at some point .

That's what I said awhile ago. She is not in the lab because of what Barry did. And I'm certain it's siren and not canary. Her voice and mannerism is too chill. Laurel was just too emotional, this one is reserved.