Sources very close to Kelley and her husband tell TMZ ... reports she already has a book deal are 100% false because "Jill hasn't spoken to any publishers. There hasn't even been a discussion with anybody about a book."
We're told Kelley is angry about claims she's writing a book because she's hard up for cash. As our source put it ... "Jill's husband [Dr. Scott Kelley] is a very successful surgeon who is very charitable, but definitely not broke."
Kelley has been under the microscope since Petraeus resigned last month when the FBI uncovered his affair with Paula Broadwell -- who sent emails to Kelley warning her to stay away from Petraeus.
We're told Jill insists she never cheated, never had an affair -- and that all she's guilty of is "receiving unidentified emails that she felt were threatening" ... and reporting them to the FBI.