“All assumption you could as easily assume that the deputies just wanted to hassle her. If they are not arresting her then she does not have to get off the bus.”
What if, for the sake of argument she had been banned from riding the bus and had got on anyway? Could the police remove her then? Or would they have to arrest her for being on the bus had she been banned?
Yes that could have been the case and then the officers should have placed her under arrest. They did not, so what were they doing.