I assume she's trying to pass in California which is one of the very few states that let you sit for the bar exam without a JD from an accredited law school or any degree at all. In exchange for allowing that California also has the hardest bar exam of any state in the union.

Also lawyers don't just go to four years of college. They have to do that and get a degree in any subject and then attend law school which in the US is only ever a postgraduate program which requires a bachelor's degree as a prerequisite. And even those who complete both of those levels of education often fail the California bar exam multiple times.

Self study in comparison would be nearly impossible and the only way to actually succeed would probably be to apprentice under a practicing lawyer for many years, learn the trade that way, take an exam prep course and then maybe be able to pass. Granted in the olden days lawyers like Abraham Lincoln didn't have any degree either and they were usually admitted to the bar after this type of apprenticeship.