Alfred and Matthew very vaguely remember a black haired baby with violent eyes that used to be with them and their mother all the time when they were really little, around three. They think it was their little sister, they're not quite sure though. Than one day she just went missing. They've noticed Alex looks like an older version of said girl, and for a while, until now (now they're all 19) she was thee physical years younger than them until Alfred and Matthew shot up. Than Alex did too, again, three years younger than them until recently.

But it was impossible for that girl to be Alex, right?