That's what I thought as well - it seemed rather explicit to me. I also think that given that you are a floater and not being able to work at one branch won't have much of an impact on your employment (if I understand correctly), your supervisor might also have you in mind with that decision. If you have such issues with many patrons at this particular location, she might find that it would also benefit you to be freed of this responsibility and work at less stressful locations.
I would be curious about how she worded the decision that you can no longer work there.