If Only Eve Had Eaten the Fruit, Would Sin Still Have Entered the World?

Questions about whether sin still would have entered the world if only Eve had eaten the fruit, the theological explanation for why Jesus did not inherit a sinful nature from Mary, and what the idea that nothing good can come from evil would mean for children born as a result of rape.

• If only Eve had eaten the fruit and Adam refused, would sin still have entered the world?
• What is the theological explanation for why Jesus did not inherit a sinful nature from Mary?
• If nothing good can come from evil, how can we justify children born as a result of rape, incest, out of wedlock, etc.?