Emma

At some point in the movie someone (Willis?) points out that sleeping in a van like she did was dangerous and she replied "I noticed that in Biloxi"; when asked what happened in Biloxi, she doesn't answer.

I assume someone assaulted her and that is also the reason why she returned to Holly Springs.

Lots of things are left vague and ambiguous in this movie which is of course good on one hand, but on the other hand - I just like to know what "really" happened :)

Aspire to climb as high as you can dream

Yes, the scene that exactly explains that must have been left on the cutting room floor.

All we have in the movie that is, is a few hints: 1) she has a slightly purplish bruise on her left jaw, 2) she has as suddenly returned to town as she had left it a few (weeks? months?) earlier as we learn from her erstwhile local policeman boyfriend, and 3) her father deserted both her mother (Camille) and his wife (Cora) before she was born. Putting those together we may assume she ran off with a guy who turned out to be a hitter, and promptly left him after being clobbered.