I think you're the first person actually answer the first question. Thanks. How about the second and third?
Sorry. I assumed your choice of the word "actually" indicated historicity, so I thought the question didn't apply.
In the story, did Adam and Eve know right from wrong before they ate the fruit? The only hint in the story is the following verse:
Genesis 3:22 And the Lord God said, “The man has now become like one of us, knowing good and evil."
This verse does imply that Adam and Eve did not have a concept of good and evil before eating of the fruit.
Could she sin prior to having this knowledge? It depends on the nuances of your particular definition of sin.
If in your mind you have to have a conscience in order to have moral responsibility for your actions, then no, she didn't sin. For example, we do not think animals sin.
However, you can have an understanding that something is forbidden without being having your own internal understanding of right from wrong. For example, your dog knows very well it is going to get into trouble for eating the dinner you left on the coffee table. That's why the dog slinks away when you come back into the room LOL.
Kohlberg calls this stage of moral development the Preconventional Stage. We all go through it between ages 0-8. During this stage, we accept the morality OF OTHERS and refrain from "bad actions" because we don't want to be punished.
The question would be, can a 4 year old sin? I think there would be some people who would say, YES a four year old does understand that stealing will get them into trouble, and is therefore responsible for their actions when they steal, which is why parents are correct to punish them when they steal. Other people would say NO, and the reason we send them to the time out chair is because we are TEACHING them, not punishing them.
My own personal opinion is that the story does seem to indicate that Adam and Eve were in this Preconventional Stage of morality before they ate of the fruit. Since I am part of the people who think that we TEACH four year olds, not punish them, the punishment of death for Adam and Eve as well as having to labor and experiencing pain in childbirth, seems over the top. It is a weakness in the story.
But remember, this is a STORY. Not reality.