As someone who has hsv2, I can promise you that if she had open sores on or in her vagina, she isn't going to be fingering herself or touching herself. That hurts.
What you are suggesting isn't rational.
While in theory, it might be possible, no one ever touches themselves and then immediately touches someone else. Movement is involved, air is involved, touching other things is involved. Using your theory - if it were this easy to transmit, everyone would have it, right?
Also, herpes is spread by skin to skin contact - direct, unclothed skin to skin. When we say this, we mean oral to oral, oral to genital/anal, genital to genital, or genital to anal. It doesn't have to enter your urethra - the mucus membrane skin of your genitals and anus are thin enough for the virus to enter. Syphilis and HPV are also spread by this same skin to skin contact. You will not get it from hugging, casual contact, through clothing, toilet seats, etc.
Many people are asymptomatic. We don't know precisely how many - we used to think it was quite high, until we realized that we had false positives on the hsv2 IgG test.
Also, many people do get symptoms, but they are milder than what a lot of people might think are typical symptoms, so they get missed or are misdiagnosed as things like yeast infections, jock itch or other fungal infections, etc.
If your only risk was the woman fingering herself and then touching you, I wouldn't worry at all.