Yeah...John Byrne was throwing out clues that a third personality was surfacing during his run, but it was never fully explored...I also think Walter's tampering with her powers may have triggered something in her psyche. Anyway, I don't think Mantlo ever addressed the third personality, that Byrne had started creating.
I like your idea with Jeanne-Marie growing into a hero, MM...It would be a very interesting storyline, I think.
Dana