There haven't been any studies done on positions and risk for herpes transmission so I can't really answer that question with any kind of certainty.
I can tell you about transmission rates. I know you know it's low, but I wonder if you know how low it is.
Assuming you were in a relationship with her (and you may be):
Ghsv2 transmission, female to male, over the course of a year, assuming sex 2-3 times a week:
Only avoiding sex during an outbreak - 4-5%
Adding condoms OR daily suppression - 2-3%
Adding condoms AND daily suppression - 1-2%
If you just had a one time, protected encounter with her, your chance of getting herpes from her is about 1 in 10,000.
Is she on daily suppression? If this someone you'd like to continue to see, perhaps she'd consider it.
For now, I don't think you have a lot to worry about, and I'd say testing isn't warranted unless you get symptoms. Does she know what type she has genitally? As you know, just because it's genital doesn't mean it's genital type 2. It could be genital type 1, as a result of someone with oral hsv1 giving her oral sex. If she has ghsv1, and you have oral hsv1, you can't get ghsv1.
If she doesn't know, she can get an IgG type specific blood test to find out. If she turns out to have hsv2, there are ways to reduce transmission if you are interested in a relationship with her.