How long was it before Adam and Eve sinned? Do we have any idea how long Adam and Eve were together sinless in the Garden of Eden before they sinned?

They were created on the sixth day. They sinned before they had children.

Any other clues as to how long they were sinless together?
Genesis 5:3 says:


  When Adam had lived 130 years, he had a son in his own likeness, in his own image; and he named him Seth.


By virtue of this, we know that Cain killed Abel within 130 years of Adam being created, 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.