Question

In O. Henry's "The Gift of the Magi," despite loving her long hair, Della cuts it and sells it. What motivated her to take this step?

Answer 1

You have to "read between the lines" to find this -- that is, you have to try to understand things that the author only implies.
So here are some clues to her motivation:
Jim only gets paid 2/3 what he used to. Della probably doesn't work. Their rooms are rented and cheap - the mirror is so narrow no one can see all of themselves. Della only has about 1/10th what she needs for a gift. What does this say about her options for gifts?
What are the two most valuable things Jim and Della think they have? What do they value more than gold or jewels.
How do Della and Jim feel about each other? You have to figure this out from how they talk to each other, and how O. Henry talks about them.