Answer: she was sad.
Explanation: The scene "The Gift of the Magi" in which Della counts her money makes me infer that she is sad. She really loves her husband and she has been saving money for several months to buy him a present. However, as she counts her $1.87 we can see how sad she feels because she is poor and she cannot afford a gift for her husband. In fact, she describes a grey cat on a grey fence that she is looking at and we can infer that her mood is as grey as the cat and the fence.