If she gets an IGG (blood) test, she can get tested for antibodies for HSV1 and HSV2. You can get either strain in either location, but HSV1 prefers the mouth area and HSV2 prefers the genitals. If she's had cold sores since childhood, she'll probably be positive for HSV1 with a pretty high antibody level.
So in my case - I had had cold sores since I was a kid as well, and my IGG number was high for HSV1 - old infection. I was tested after my ex's encounter with the escort. His IGG number for HSV2 was higher, indicating that he'd had it for a while, but mine was quite low, despite the fact that we'd been married and having unprotected sex for a while. Since he hadn't touched me between hookergate and my testing, I had to have caught it before that. But probably after YEARS of unprotected sex. It's likely my having HSV1 provided me some protection from HSV2 and is probably why I don't have symptoms.
I didn't know all this at the time. I got my results and called my OBGYN's nurse line to ask questions, and the nurse basically slut-shamed me. Exactly what I needed after being cheated on by the 3rd person I'd slept with ever, the ONLY person I'd had unprotected sex with, my husband, the father of my children. Still salty.
Post separation (2018), I called the OBGYN again and talked to a WONDERFUL nurse. She told me my HSV2 IGG number from back then (2010) was so low that it might indeed be a false positive and urged me to get another blood test. This time my number was much higher - because those antibodies had had years to build up.
I literally never think about it now, it has no effect on my life, other than the couple of times I had to disclose while dating. The stigma is FAR worse than the actual virus. Frankly I'd rather get outbreaks down south than the stupid cold sores I get when I accidentally have too many walnuts or too much chocolate - would be easier to hide!
[This message edited by JanaGreen at 6:05 AM, July 15th (Wednesday)]