Do we have any idea how long Adam and Eve were together sinless in the Garden of Eden before they sinned?
Any other clues as to how long they were sinless together?
Genesis 5:3 says:
By virtue of this, we know that Cain killed Abel within 130 years of Adam being born, because Seth was not born until after that occurred. This means that the Fall had to occur within that time. Other than that, the Bible is silent.