How should i deal with this awkward woman?

I'd openly just ask her. Don't be rude or impolite, and try to say it discreetly. Just tell her that you get a feeling that she has a problem with you and would like to know what you did/how you can fix it. It makes you seem adult and if after that she still acts like a b*tch towards you, just ignore her and try to sit somewhere else. Good luck!