I think that, though not too awfully common, there are instances where someone suddenly gets a "wake up call" as it were in respect to certain things in their lives (usually in regards to a psychological viewpoint)--a sudden realization or understanding, a new perspective that they never saw (and typically couldn't see) before. It's as though the 'scales fell off of their eyes'.
I'm not entirely sure yet what will come from Jolyne's realization, but I'm choosing to interpret this monologue of hers as one of those moments of (almost supernatural) clarity.
Therefore, I personally don't see her situation as unrealistic, just quite uncommon!