It's a little ambiguous. But it appears she collapsed and Amina from main universe now has the memories of Amina from universe-saved -five-strangers. Given it's comics, this could be physical swap or mental transferracne or possession, but generally such things are somewhat reversible. So main-universe Amina could return/be rescued/seem to return and the heroes acept it because heroes, in general, are trusting spouls who can be fooled by a convincing liar who invokes the tropes of the setting, i.e. possession, mind-swaps, etc, etc.
Or it just could be an implanted memory so that whomever did it had another tool to use against the F5.
Or it could be she's just insane… 
Too simple of an explanation. This is comic books!
Works with the Joker.
"He fell down a mining shaft filled with vipers and scorpions, after which it exploded. HOW IS HE STILL ALIVE?"
"Because he is insane!"
Yes, but he was introduced insane.