I haven't battled Penelope yet, but by watching a few battles, her team seems like pretty solid already, but I wouldn't mind too (as sailboat stated). I mean, increasing her array of options is always good for a player that is already restricted with a type, so...I vote yes for M-Charizard X, but, would she be allowed to keep Charizard without mega evolving (who knows if that could help her someway)?