She can not transmit what she does not have. If she is not infected with hep c she is not infected and cannot transmit an infection she does not carry.
There are some who were infected in the past with no idea how this happened. If you only have hepatitis c antibodies there are a few instances that can cause a false positive even if you were never exposed to the virus.
About 25% of people are able to beat the virus on their own with no treatment.
So if you test negative fro the virus with the HCV RNA by PCR test either you are having a false positive or you may have been able to beat the virus on your own. There is no way to determine the cause for a positive antibody test with a not detected HCV RNA test.
A false positive occurs when the ELISA test comes up positive for hep C antibodies, but the person taking the test was never exposed to hep C virus, which leads the RNA test to read as negative.
The problem is that antibodies that the immune system has produced to combat infections other than hep C can be what’s known as “cross-reactive”: The ELISA winds up picking up on these antibodies’ presence and incorrectly coming up positive. Research has shown, for example, that people are much more likely to test false positive if they’re living in areas of Africa where exposure to infectious diseases such as worms is more common. “There are a myriad of things than can infect you, particularly in areas where you don’t have a lot of sanitation and clean water,” says Oliver Laeyendecker, PhD, an infectious disease researcher at the National Institute of Allergy and Infectious Diseases.
Those who test false positive, regardless of the reason, will likely continue to do so for the duration of their lives. So in the event of future hep C exposure, an RNA test will be needed to accurately diagnose an infection. Major risk factors for contracting hep C include: injection drug use, including steroids; the sharing of needles, syringes or other injection materials; needlestick injuries in a health care setting; tattoos or piercings performed with non-sterilized equipment; and condomless sex among HIV-positive men who have sex with men (MSM).
There is also always the rare possibility of lab error leading to a false positive or a false negative test result.”