Awww look... the commenters can learn. Finally.
But heck, she might not die. It just depends if the story errs on the side of the formulaic or aims for a twist.
Oh sure, I mean everything so far suggests she'll die... Very very strongly. But if the same thing happens every single arc, the story would get boring, wouldn't it?
... Okay, so she'll probably die and it is too early for the doppelganger to learn to actually save anyone... but we can but hope, eh?