So, if I'm understanding correctly, you only had protected oral with her - not vaginal or anal sex?
If that's the case, and she has genital hsv2, you aren't at risk at all from this for hsv2. People with genital hsv2 are only infectious from their genitals.
Also, I'm not sure where the 1.5% risk figure comes from? That sounds like the stat for if you have vaginal sex with her, and she's on antivirals, but that's the risk for the course of a year, assuming sex 2-3x a year, not per encounter.