There is no risk here. Saliva doesn't transmit herpes unless it comes in contact with a sore, and you don't mention that she had a sore present. (If she had one, you'd notice and you'd have mentioned it.)
Even though you tested negative, the hsv1 test misses 30% of infections, meaning there is a decent chance you have it and don't know it. The vast majority of people who have it will never get symptoms, and it's very common. 67% of people under 50 have it globally.
In any case, your test is negative, and your doctor has told you 3 times that you don't have anything. You can let it go.