Low oil level

Not only what was said above but also if her brakes fail she can take you to court, same with the engine or anything of hers you touch.
Or god forbid that you get into an accident while “test driving” it - no insurance coverage for that.
I had the same situation
a corolla with about 1 cup of oil in the crankcase.
Clogged pcv valve.
Changed that and the oil and the car ran for years no problem.
With a cup of oil coming out I could not believe the engine wasn't toast