I have this theory that Mari isn’t 14 at all, she’s secretly like 18 or 19. That’s why none of the plugsuits fit her breasts and it’s also why she knows so many secrets about NERV/Seele/the Eva. She seems more mature than the other pilots, even to the point of advising Shinji on what to do while still understanding his situation. It may also explain why she can pilot any Eva without them going berserk, although that might require her to have high levels of dopamine/whatever other neurochemicals are required to pilot.
I am a huge fan of this theory. Also had to reblog twice ‘cuz I didn’t want part of the text cut off.