It's all in your mind then, I wouldn't worry about it too much. That is the problem, though, that it's so difficult not to worry about it, it seems impossible. It's a circular thing, a cycle, where it happens once for whatever reason (lack of sleep, diet, exercise, just having an off day, having a partner who puts fears in your mind), and then next time you wonder 'Will it happen again?' Sort of like a self-fulfilling prophesy, I think it's called?
I guess only you can decide if the woman you were with caused any of this. And if she is 'honest' or if she's just a jerk. You said yourself that she's self-conscious, and if she makes fun of her parter's genitals then she's probably trying to make herself better that way. Sort of like how bullies pick on others because they feel inferior. That's just something to think about. But then again, you don't really sound like you want a relationship with her, so perhaps it's a bit irrelevent?
If it's just a casual thing then just go for it next time you're with her, don't let her bring up her past boyfriends, and I bet it'll all go smoothly
