"I heard you usually get whitlow the first time you get herpes" - you may be talking about autoinnoculation. This is where you infect yourself in a different location before you have antibodies to protect against this.
If skin has already grown over, you're fine.
Here's a good thread from one of our doctors, when we had them - in his 30 years of practice, he's never seen whitlow - https://www.medhelp.org/posts/STDs/herpetic-whitlow/show/249050
There's no need to call the girl and ask about herpes. Even if she has it, chances of you getting it on your finger are so, so low that you don't need to bother her with this.
Try to not think about the "what ifs". That's anxiety talking, not reality. You'd have to have open skin, like an actual cut. You didn't, or you'd see it today. You don't.
Seriously, consider getting some help for this anxiety. I say this with only compassion. There is help for this. Remember that guilt does not equal risk.