According to the story, God took both Adam and Eve to the Tree "Hey .. you two! C'mere! See this Tree? Don't touch! Mine!" (yes, I gave God a Brooklyn accent). So Eve knew from the start not to touch, but she wanted it anyway and probably more so now that she was told no. So the Serpent (which is Temptation) talks her into it and she bites the apple. Nowhere in that lore does it say she had to take time to digest this, so we can safely assume her gaining that Knowledge of Good and Evil was instantaneous. She knew now WHY God said no. Now we come to the part everyone glosses over: she had a choice. At that moment, knowing what she did, she had a choice. She could have presented herself to God for judgement, apologizing for eating the forbidden fruit, and kept Adam out of it. Instead, she chose to rope the poor guy into it so she doesn't have to be alone. Shared sin is less terrible, to some minds. Three bad choices, three curses, and bait for fallen angels.