I had lice when I was in preschool.
Had them again in college.
Huge portions of the world, including much of Europe, have lice and they don't care. America is overly uptight about it.
Rid shampoo and a very fine tooth comb (usually comes with the shampoo).
If you are a guy, shave your own head down to a one and they will go away quickly.
they hang out mostly around the ears and the nape of the neck.
If you think that you might feel itching, then your brain will trigger more itching - it is a normal response that happens.
Unless you were rubbing against this woman, sharing clothes, sharing hats, or rubbing your head on things that she had been rubbing her head on (a very tall seat), then you don't have lice.
They can't jump over to you, so you are safe.