Some people have more outbreaks and more painful outbreaks than others. It's helpful to take an antiviral that suppresses the outbreaks. When there are no outbreaks, chances of transfer are low but not zero. It's tends to be higher risk for the penetrated party rather than the one doing the penetrating. Since she never had an outbreak and the penetrated party is less likely to transfer, this may be why.
Frankly, though, like all viruses, long-term effects can be kind of scary, like the evidence of a correlation with higher rates of alzheimers and dementia in patients with HSV-I/HSV-II. Viruses do a lot of things to the body long-term that may not be readily obvious or related directly to the virus itself, much like human papillomavirus is correlated with higher instances of cervical cancer and throat cancer. Long-COVID is another example.
While transfer probability is low, it's still valuable to try to stop transmission by using prophylactics.
I think I’ve had two outbreaks before this third one. I can see why someone wouldn’t know. It just looks like a patch of ingrown hairs. Doesn’t really hurt or itch very much. I wrote it off until someone contacted me. (I’m in the States, I’m not going to the doctor unless I’m about to die - I do test for all of the other things regularly because that can be done OTC or free sometimes.)