In the abstract, Faulknet portrays Emily as a symbol of a dying Old South, a "monument" of ancient times, stubborn to let go of a glorious past, and unable to fit into the present. She is a vestige of what once may have been glorious, a little girl alone, a woman lost due to the lack of control exerted by her father, and a woman so desperate for company that she would not even let go of the dead bodies of her father, nor her lover.
Concretely, Faulkner describes her in the beginnings of the story as:
They rose when she entered-a small, fat woman in black, with a thin gold chain descending to
her waist and vanishing into her belt, leaning on an ebony cane with a tarnished gold head. Her
skeleton was small and spare; perhaps that was why what would have been merely plumpness
in another was obesity in her. She looked bloated, like a body long submerged in motionless
water, and of that pallid hue. Her eyes, lost in the fatty ridges of her face, looked like two
small pieces of coal pressed into a lump of dough as they moved from one face to another while
the visitors stated their errand.
It is a little hard to know what you mean by how she is portrayed. Do you mean physically, or her state of mind, or what?
As far as her personality, I think the main thing that stands out about her to me is the fact that we find out she was crazy. At least, it's crazy to me for a person to sleep with a dead body for thirty years.
Less obviously, she is pretty arrogant -- she sees herself as better than other people due to the fact that she came from a "good" family. You can see that from how she treats the people who come to ask her to pay taxes.