Originally Posted by
FUBAR007
The thing to keep in mind is Jean would've been around for the Shi'ar slaughter of her entire family in "End of Greys" as well as for the revelations of Xavier's lies about Danger and Vulcan, and all that would definitely have had an effect on her emotional state. She would've become angrier, edgier, and less stable just as Scott did. The question is how badly and for how long.
A lot also hinges on whether or not she would've retained the Phoenix Force. If she had, could she have prevented M-Day? Or at least immediately reversed it? Would Hope have even come into play? Would AvX have even happened?