What you describe is not unlawful harassment. Since she's rude and nasty to everyone (Other co-workers have complained about this person. She has problems with everyone (the operations manager, shop supervisors, and other co-workers), she's clearly not singling you out because of your race.
It's too bad that when someone reported the racist remarks she was making and the boss came and asked if it upset you, you minimized the situation instead of being truthful and telling him that your were offended. You can do so now but your comments won't be very credible since it will appear like you're simply trying to throw some mud on her after she made the SH complaint against you. And by the way, unless there's considerably more to the incident than you related, the comment you made in no way constitutes sexual harassment.
All you can do right now is sit tight and hope your employer makes the proper decision and sees her as the problem, not you. What you should do from here on out is to steer clear of her as much as possible. Do not engage in any casual conversations with her or even be in proximity of her if you can at all help it. And if she makes any racist or other inappropriate comments, report them to the boss right away.