So let me be certain that I understand what you are saying here:
You got a low positive HSV 2, did the western blot and are negative for HSV 2, positive for HSV 1.
The got an IgG test and is also positive for HSV 1 and negative for HSV 2.
So you are the same?
There is not way to know if her HSV 1 was present before you gave her oral sex or not. If she doesn’t have symptoms genitally, then a good chance she was infected prior to receiving oral sex from you.
I think it is high enough to assume she is indeed infected with HSV 1 and since you both are, giving oral sex is not a concern.