A small, white spot that stays there is not what herpes looks like. Oral herpes looks like a scab that stays for a week an goes away, then comes back sometime. Show a doctor next time you go, so you'll know for sure.
A positive herpes 1 test means nothing, just that someone had herpes somewhere on the body sometime, and your girlfriend already knows that, As for the herpes 2 test being low, so it might be wrong, I don't really know what that means. If it's low, then it's negative. Anyhow, that has nothing to do with oral herpes. If the doctor thinks the herpes 2 test--which is for genital herpes--is unreliable, then the test should be repeated, so they'll know for sure, one way or the other. But again, that has nothing to do with oral herpes.
Best.
Dr. Rockoff