Pysically, in the beginning of the story, Della is a georgous woman with the most stunning hair imaginable. It went all the way down to her knees and people looked at her in awe. They would have seen her hair and compared it to the most beautiful women of the world and those women would not have compared.
In terms of personality, she dearly loved her husband and sacrificed her most prized asset, her most valued feature to be able to generously give him a Christmas gift. She was a frugal person of both "prudence and reason". Upon arriving home and looking at her hair after it was cut, she quickly got to work repairing the damage done, but the best her appearance could afford was that of a "truant schoolboy". Her hair being gone stole some of her luster as a person.
In this story, Delia Young is a very nice young woman. She is unselfish, brave, and loving. She reacts well to being in tough situations.
We know that Delia is a beautiful young woman -- her hair is lovely, her husband likes the way she looks. We also know tht she may be at least a little insecure as she worries that her husband will not be attracted to her anymore once her hair is cut. Although she feels this way, she has gone ahead and cut her hair, showing how brave she is.
Delia is unselfish. We can see this in how she sells her hair because she wants so much to buy a gift for Jim for Christmas. This also shows how loving she is.
Finally, we see her react well to adversity. First, she finds a way to get Jim a present even though they are poor. At the end of the story, moreover, she reacts well to the situation they are in.
And here I have lamely related to the uneventful chronicle of two foolish children in a flat who most unwisely sacrificed for each other the greatest treasures of their house. But in a last word to the wise of these days let it be said that of all who give gifts these two were the wisest.
O. Henry's narrator intrudes upon the ending of "The Gift of the Magi" to make the ironic observation that Della and Jim Dillingham Young were "foolish" and "unwise." Then, the contrast between what they really are is stated in the next sentence: "these two were the wisest."
Della, who subsides from the "first stage" of crying and feeling sorry for herself that she has no money, moves to the "second stage" of doing whatever she can to give a Christmas present to her husband, whom she loves with complete unselfishness. For, she sacrifices her most treasured possession, her luxurious hair.
This young woman of O. Henry's classic story is the antithesis of the young women one reads about in the magazines on the rack at the grocery store checkout, or many of the young women from the reality shows. How often is a remark such as "He knows he better buy me a diamond ring that is x carats," or "I told my parents I want a new car, not some old, used thing," etc.? Della, who is unselfish, knows that real love has no connection to material or physical possessions. This "unwise" and "foolish" characteristic of Della is one that is more beautiful than even her dazzling hair.