Interesting case but I think I can help you understand it. False positive cultures or PCR tests from a lesions are rare. I would likely believe the swab test in this situation, especially since it was also typed AND if it came from a lesion. You could talk to her about those circumstances. When a person takes antiviral medicine (Valtrex) daily when they are first infected, they can delay antibody development for weeks or even months Normally, if they are taking medicine daily, this is not an issue because the medicine is in essence taking the place of the immune response and helping to keep outbreaks under control. However, because the immune system is not seeing the virus because the medicine is stopping or reducing viral replication, antibody is not produced quickly and sometimes not at all. This could be why she has no antibody yet.
As for you – It’s possible that your low positive for HSV 2 is a false positive. It is in the range where there is about an 85% chance that this is a false positive. Yes, it could also represent a new infection and the number could certainly go higher. It is also possible that you have been infected all along and just maintain a low positive HSV 2 antibody index value, since you mentioned at the start of your post that you have not been tested for herpes. Is that correct? Unfortunately it is likely too early to retest using a western blot.