In Class Work

I think that the reasoning is that Aunt Alexandra told Atticus that Jem and Scout need to start acting more like a Lady and a gentleman because she fears that they will ruin the Finch family reputation. I think she meant that he was trying to be convincing and telling them that he is becoming more like Cousin Joshua and he hopes he doesn't cost the family 500 dollars and he means to tell them that if they keep acting the way they do and they don't start acting like a lady and a gentleman, then they will become like Cousin Joshua and cost the family 500 dollars. In conclusion, I think that when Scout says only a woman can do that job, she means that only a woman can be that convincing.