You should be avoiding oral sex until she is all healed. Otherwise if you have hsv1 orally already you aren't likely to contract it genitally later on. Still err on the side of caution and if your gf has oral symptoms - don't let her perform oral sex on you until they are all healed.
grace
Is it likely for me to get genital herpes from HSV1 if we participate in oral sex?
It was a visual diagnoses.
Oral herpes is almost always caused by hsv1. Over 60% of adults in the US have it orally but only 20-40% of them ever get obvious cold sores to know that they are infected with the virus. It's incredibly common and not many of us make it to the old age home without it. You didn't say how your gf was diagnosed with oral herpes - did the doctor just do a visual exam or did he also do a lesion culture and typing? If indeed this is hsv1 orally - since the lesions are on the area you described it is most likely a newly acquired infection. Recurrences tend to be outside the mouth area but a newly acquired infection can be inside the mouth/throat area. She most likely got it from kissing you.
Hope that helps with your questions :)
grace