A girl in the Old West becomes the town judge, just before her outlaw aunt shows up.

Like I said, make it work in the world of the story, maybe it's a very small town, perhaps it's very isolated, perhaps they're a micronation... as long as the world's rules are set up in the beginning, it no longer matters what the situation is in the "real" world. This is the wonderful thing about writing, there are no rules until you make them.

A person can choose to be a lawyer (or a doctor), but in the US you can't chose to be a judge just because you want to or because it's family tradition. Judgeships are elected positions or political appointments.

There was the Judge Roy Bean scenario, outposts of civilization where one man acquired the position of judge (and sometimes sheriff, too) by brute force and intimidating reputation. But that was the exception, not the rule, an exception it is difficult to conceive a woman having the "cojones" --literally and figuratively -- to pull off.

A person can choose to be a lawyer (or a doctor), but in the US you can't chose to be a judge just because you want to or because it's family tradition. Judgeships are elected positions or political appointments.

There was the Judge Roy Bean scenario, outposts of civilization where one man acquired the position of judge (and sometimes sheriff, too) by brute force and intimidating reputation. But that was the exception, not the rule, an exception it is difficult to conceive a woman having the "cojones" --literally and figuratively -- to pull off.