Originally Posted by catfeeder
Low income people are naturally frightened. Skip the indignation to help yourself approach this from a more effective angle--compassion and logic.
Let her know that you've been eating her taxes to help her, but the new job will not do that. Show her on paper how the taxes will harm her, and ask her if she's willing to take the night to reconsider. Let her know that if she opts to continue the bus thing, that will be her only income, because you'll need to hire someone who can work the whole shift.
It's not good for your own head to view her through a lens of ingratitude or disloyalty. The woman is poor and not-so-bright. Let that be your compassion platform, and see if you don't get better results for your own stomach lining.