It's really not clear to me why they are saying bipolar at all, which probably explains why they suggest "quotes" around it. (Well, that and her age. It's dicey business trying to diagnose something like bipolar at that age, and consequently, many practitioners will be tentative about it.)

You asked, "Are these moments where she can truly be "verbally aggressive" an example of a manic moment?"
I'm going to say no, mainly because mania isn't about moments, it's a sustained state of being. Moments suggest acting out, perhaps her idea of what bipolar is(?) Or the frustrations associated with that age?

I will say that I can see in what you describe, the other dxs they've thrown out there (borderline, factitious disorders and your mention of her narcissism). Unfortunately, I have no ideas for you how to motivate her to want to get better. She knows what she's doing, and for her, the results are a payoff. How to eliminate *wanting* that payoff? Who knows. Have any of the professionals had ideas? My only experience has been in dealing with an adult with these proclivities. I feel your frustration in trying to understand what seems to make so little sense.

Sorry this isn't more helpful. My heart goes out to you.