The test should ensure that a driver can read read and understand street signs both symbolic and textual ones and respond correctly ... oh yeah, and drive the relevant vehicle. They should also be able to service the car sufficiently to keep it safe - pump tyres, check fluids, know mostly when it needs attention from a mechanic.

Not everyone can do all these things hence the test appears "inaccessible".

I see three possibilities. If these words are as normal in Korean as they are in English, then she failed to learn them because (possibility 1) she was so sheltered she actually had no exposure to basic knowledge required of any competent driver or (possibility 2) she has an intellectual disability that prevents her from learning new words and concepts without a lot of help. In these two cases, you can't blame the test.

Possibility three is that the words for used on the test are government legalese that is never used in real life, and she did not understand that learning what they meant was a better strategy than trying to memorize entire sentences from the driving manual. In this case the test is partly at fault, but an intellectual disability would probably still be involved. (Though perhaps you could also blame educational traditions that stress rote learning and glorify hard work as a sufficient solution for any problem.)

I guess all three of these scenarios require her to have some kind of intellectual disability, because even in the first scenario, a normal person could learn everything she needed from the test-prep books. Also, I doubt anyone would celebrate her persistence if it was a story of a person with normal intelligence who threw away so much time and money retaking a test she should have known she wasn't prepared to take again. It would be perverse or at best eccentric, not inspiring.