so maybe the new killer ash is like she's been goaulded. her real personality taken over and locked away and supplanted by the 'new' one
so, theories to fixing her...presuming they can catch her without getting killed themselves (a sure bet if they're talking season three )
they use the one essex girl to 'erase' ashley's gifts and rewrite her, like the cabal did to the others. but will or can helen make ash the way she was before or will she make her something 'better' or make her 'normal'
maybe that's the only way to save her is to make her a regular human
imagine ashley dealing with that