You have a couple of potential options.The first is to go and talk to the HR (human resources department) to raise a concern about workplace harassment.  Sometimes this will resolve minor issues before they get worse. A second option is to arrange a consultation with an employment law attorney.  There has to be a motivation behind her actions.  If she is simply a horrible person to everyone, then you won't have an employment law complaint.  However, if her actions are based on some type of other bias (gender, races, sexual orientation), then you may have a complaint for workplace harrassment.  These types of complaints usually have to be filed first with the government agency, then you can file a lawsuit, if needed.