Using textual evidence, how do we know that Della is nervous about cutting her hair?
Della’s hair has always made her feel special and proud because it's unusually long, reaching “below her knee.” Described as "the most valuable thing" she had, her hair is also a matter of pride to her husband Jim.
Della loves Jim more than anybody or anything else in her life. Finding her savings insufficient to buy him a nice present on Christmas, she decides to do away with her hair, though she knows even a queen would envy her with that hair.
Of course, this was not an easy decision. Parting with her hair would be her last alternative. When she has settled with this idea of selling her long hair, she stands before the mirror gazing at her prized possession for the last time.
“So now Della’s beautiful hair fell about her, shining like a falling stream of brown water. It reached below her knee. It almost made itself into a dress for her.”
She thinks she must buy Jim a gift that should be “something nearly good enough. Something almost worth the honor of belonging to Jim.” At the cost of her hair, if she could make this Christmas special for Jim, she wouldn’t mind doing it.
But that also means she would lose her unique and enviable possession. This dilemma, though, lasts for a while, and makes her feel nervous, as reflected in these lines:
And then she put it up on her head again, nervously and quickly. Once she stopped for a moment and stood still while a tear or two ran down her face.
Her uneasiness is exhibited from her nervous quick gestures and movements. The tears in her eyes reflect how much she will miss her hair. Nevertheless, her love for Jim triumphs over her nervousness and once she has left home, she doesn't rethink her decision.