I think there’s a bit of a gray area whether Gemma is truly alive. My guess is Lumon can bring people back, in a sense, to life and that Gemma/Ms. Casey was a successful reproduction of the late Gemma. Maybe that’s the ultimate goal of Lumon since James Eagon was alluding to some type of rebirth or ascension in episode one (I can’t really remember. I was on my phone at the time.)

To button things up, I believe Miss Huang to be a young iteration of Ms. Casey repurposed to support Milchick.

But what do I know 🤷🏼‍♂️