She isn't lying when she says she wait for the day when Mireille will kill her.
There's an odd sense of rightness to the idea that the blond woman will be the one to end her existence, a sense of balance. She doesn't understand where it comes from, only that it is there, another tiny facet of what she cannot remember.
It almost makes her happy, knowing that her death will be at the hands of someone who knew her. She won't be just another face, just another kill. She is someone to Mireille. She has likes and dislikes; they share memories.
She won't disappear.