Rei is basically trying to keep denying to herself that if she succeeds in her mission, then countless children of various ages all over the world would be put in the exact same position she found herself in, and worse, all for her own happiness that isn't even guaranteed; simply going on the word of a talking crow (a bad omen in itself), with glowing red eyes (even worse) that appeared out of nowhere.
__________________
"I'll show you that a superior mobile suit has its limits when it goes up against a superior pilot!" - Char Aznable, The Red Comet
"Come on! I don't feel like losing!" - Johnny Ridden, The Crimson Lightning
"Hatred is the root of all war! That's common sense, boy!" - Anavel Gato, The Nightmare of Solomon