sonnyjimjr3, I've been taking a slightly different approach for this story, trying to distinguish it.
I wanted to send a note to distinguish what I was thinking. The idea you proposed was that you wanted to explore the idea of it being hypnosis and suggestion.
So, Miss Fine appears to break down people's resistance and plant a life-changing thought in their head. Then, I would assume, guides it in a direction she wants over subsequent sessions.
The question is what her agenda is, but I sort of like it not being clear for a long while. And it may be that the decisions she makes do have something to do with the person she is manipulating. Or each could be an independent experiment.
So far, what will likely happen with Jon and his mother is established. Which leads me to think about Sarah, Zoe, and Tiffany.
Sarah seems to want what Karyn has. There's a lot of fun we can have with that whether we keep Karyn secretly investigating the situation(whether doing so while changing herself or not) or if she stays away from Miss Fine and all the manipulation comes externally.
I have a few ideas about how the Sarah-Karyn thing might play out.
As for Zoe, I would assume, with two cheerleaders having life crises, there might be openings on the team for her to try for.