If you want to see good child actors in a 'southern film'
Watch the 1962 film "To Kill a Mockingbird".
This was awful in regards to child actors, the worst one being the little blonde girl.
When you say "southern film" I will take this as meaning, a movie that was set in a southern town. The fact that this was set in the south had little bearing on the storyline overall. It could have happened anywhere in a small town.
The problems that I believe you are referring to, have to do with the "dialect" and accents. I had absolutely NO problem with the dialect except for the girl you mention.
I dont usually do this but this is a copy of something I wrote in a different thread:
To me she was the weakest link in an otherwise enjoyable movie.
Here is the problem with the accent: People all over the country (and outside the country as well) will be watching the movie. Many, if not most, of the viewers will be a younger audience. Most will not be exposed to, or have connections to the south. I, as an adult, found most of her dialog, incomprehensible. I had absolutely no problem understanding anything that anyone else in the movie was saying. The acting on the part of the rest of the kids was excellent, in my opinion.
I am not saying that she is a bad actress. I am not familiar with her whereas I AM familiar with the 2 male leads and they are pretty well known for their good work. Nevertheless, when a movie produces dialect that people cant understand, it is losing a part of its audience. It was out of place with the rest of the movie and in MY estimation, the accent should have been "toned down" quite a bit or find someone that could deliver the lines so we could ALL understand them.
I dont blame the kids for this. The directors are in control. THEY should be making the necessary judgements and corrections.
Again, OVERALL, I liked the movie very much.