This is mostly a good assessment, but the maintenance cost should be reduced - one part of Uber's lending program is covered routine maintenance. Gas at least should be deductible, I don't know whether the car payments can be counted in whole or in part.

The overall point is well taken, though. There are several hits to real income for Uber drivers that aren't shared by other types of low-wage worker, and while "set your own hours" offers more upside than a normal part-time job, it's limited by how many high-demand hours there are in a week. Rather than extra overtime pay, I imagine hours past her current 28 would give steadily diminishing returns.