She has a good lawsuit on her hands if she decides to file it. Courts have found that restaurants are similar to common carriers (like airlines and hotels) and must take all customers as long as they are not overtly disruptive in some way, i.e. like smelling to high heaven, or drunk and disorderly, or physically or verbally abusive. Where you may work (as long as your work is legal) or your politics are not exceptions to the common carrier doctrine in civil law.