First off, it's always a bad idea to try to get Elly to compare herself to other people or to ask her to see things from their point of view. The blinders on her mind's eye leave her convinced that everyone in the world knows exactly what she knows and only that. The idea that there are things that she doesn't know or things that she's never experienced make as little sense to her as having to sympathize with people who do things that bother her. Since all perspectives are the same (hers), it makes no sense to her that other people might not react to things as she would.
Second, it isn't a very smart thing to ask her to keep her little victories to herself. The woman lives and dies for the approval of others. While this statement might seem to contradict the idea that everyone thinks exactly as she does and are thus as likely to look at her and see a fat, ugly, fat woman who is fat and ugly and unworthy of love and affection and acceptance, having everyone praise her for being thin and beautiful and loveable and worth love and happiness and good things means that for some reason, an evil, conflict-causing MAN has somehow gotten inside her and is lying about her. Telling her to not seek approval is telling her that she's never going to succeed so is a very dumb thing to do.
So is telling her to take things slowly. While she herself loves to tell children to pace themselves, she wants to be thin and gorgeous and worthy of having nice things and love and happiness that her ten pounds, thunder thighs, large rump (but NOT HER STOOPED SHOULDERS THAT ONLY MAKE HER LOOK FAT WHEN SHE ISN'T!!!!) deny her as soon as possible. The idea that things take more than five seconds to accomplish is a bad idea because instant happiness takes too long for a boomer imbecile like her.
Finally, never use self-deprecating humor on a literal-minded dullard like Elly. The Elly of 2014 is still angry at the John of 1982 for getting Ted's directions to his 'humble little cabin' wrong but she's also still angry at Ted for 'lying' about its condition because she doesn't see that the Elly of 1982 was so damned stupid that she made an idiotic assumption owing to an inability to process sarcasm. Trying to jolly Elly into a good-natured acceptance of the certainty of set-backs isn't going to work because her brain tells her that Annie is admitting weakness.