[He] said, 'for in the day that you eat of it you shall die' ─ and since they were going to die anyway, that has to mean 'you'll die the same day you eat it
Didn't I answer that earlier? I said the story seemed to me to read as though the Snake already knew what God said. And I added that the Hebrew word in the text also means 'subtle' as well as 'crafty' and is translated 'subtle' in the KJV and my preferred RSV.
She was not ignorant of what God said (since we can assume Adam told her).
She simply had no way of knowing right from wrong, and that was because God chose to keep them both ignorant.
So if you're looking after a four-year old, and you say, 'Don't run out on the road because you'll get killed by a car', and the five-year old runs out on the road anyway, though doesn't get hit by a car, is the running out on the road the four-year-old's fault, or is it your fault as Person In Charge? I can tell what the law will say about that.
Neither Eve nor our four-year-old knows right from wrong.
And as I repeat endlessly, the story isn't about disobedience, never once mentions sin, never once says death entered the world as a result, never once touches on the concept of 'the fall of man' or 'spiritual death', never once mentions a need for redemption.
They're simply not in the story, and Paul is simply wrong on the face of the record when he suggests otherwise.
And the reason why God booted Adam and Eve out the Garden is in the text loud and clear, except you're too busy trying to impose Paul on the text to notice:
Genesis 3: 22 Then the LORD God said, "Behold, the man has become like one of us, knowing good and evil; and now, lest he put forth his hand and take also of the tree of life, and eat, and live for ever"─ 23 therefore the LORD God sent him forth from the garden of Eden, to till the ground from which he was taken.
Quick quiz: Why, according to the account in Genesis, did God expel Adam and Eve from the Garden of Eden?