Apart from the sudden “unblocking” of her suppressed love to her father, a certain “extinction event” could play a major factor in filling her with new zeal, no?

I’m not surprised that Rey is winning the popularity contest with the crowd. While both Jyn an Rey had ruined childhood, Rey came out of it energetic/spunky/[whaddyacallit], while Jyn had developed depression. Nobody likes to hang around burned-out, depressed people, we only like to watch fictional ones in Oscar-worthy dramas.

She’s probably the most realistic hero of Star Wars.
During my first viewing my jaw dropped when she was saying her sobering lines.