How is the protagonist changed or tested by the story's events?

Since the story is told anachronistically, one would have to trace Emily Grierson's mental breakdown to its earliest inception. The reader is told that Emily grew up with a domineering father, who constantly watched over her and prevented potential suitors from approaching her. Emily's experience growing up in a home with an authoritative father greatly affected her emotions and mental state. Following her father's death, Emily refuses to acknowledge that he is dead but eventually capitulates to the ministers and doctors' requests to bury him. Emily then becomes extremely ill and remains indoors for many years. The community does not see Emily for an extended period of time until she begins having a relationship with a northerner named Homer Barron. Despite the community's negative feelings regarding her relationship with Homer Barron, Emily continues to date him. The townspeople then mention that Emily mysteriously bought arsenic over the counter, and the citizens no longer see Homer Barron in town following her purchase. Emily remains reclusive inside her home, and the citizens are forced to spread lime throughout her yard to quell the awful stench coming from her estate. At the end of the story, it is revealed that Emily had murdered Homer Barron and had been sleeping next to his skeleton.
One can assume that Emily's oppressive childhood under the constant supervision of her father dramatically impacted her mental stability. Her father's death also played a significant role in her decision to murder the man she loved and remain reclusive for the rest her life. The fact that Homer Barron was a transient man could also have impacted her decision to kill him.