First let me stress that i am not an expert on this matter but have done a vast amount of research on this topic in the past few months after a herpes scare. I have also talked to a variety of professionals on the matter as well in my research.
HSV-1 is very common, it is simply cold sores which around 50% of all adults have. It can be transmitted through simple kissing, so do not freak out that u have it, or that your partner has it. It really is not your fault. By being infected with HSV-1 your body builds up antibodies. Both IgM and IGG specific (for each specific type). The transmission of HSV-1 from her genitals to her mouth is unlikely unless she touches open lesions and then touches her mouth. B/c she has it, she already has antibodies to fight it as do u (assuming u do have the virus) so it is harder to transmit it to other places in your body b/c your body already has a mechanism for fighting the infection. Same goes for transmission to your genitals although definitely possible, it is not as likely if u werent already infected. The good news is that HSV-1 is less severe in the genital region b/c it is not its "home turf" so to speak usually outbreaks are milder and occur less often compared to HSV-2 infection in the genital region.
I would suggest talking to your doctor or to MD Handsfield or MD Hook on the matter through this site about future oral sex guidelines. Hope that helps
Most likely your partner's genital HSV1 came from you via oral sex, as you know you have it orally. I am in the same boat; my partner had oral herpes all of his life, but rarely had cold sores. He transmitted it to me via viral "shedding", when the virus is active but there was no cold sore.
The good news is, you both have it, and thus have antibodies, so you really don't need to do anything differently. You having it orally gives you significant protection against getting it genitally. Genital HSV1 sheds very infrequently and outbreaks are few as well. The only thing you should do is refrain from sex when she is having an outbreak.
As to autoinnoculation, it is very rare. And, many folks who get it genitally get it orally at the same time, but unless your GF has oral symptoms will she ever know if she acquired it orally at the same time she did genitally.
And no, you can't ping pong it back and forth, or cause outbreaks in each other.
A good resource to read more is in the Herpes Handbook, here: