Answer: I don't know if this is a multiple choice question or not, but I would contend that what the excerpt reveals about the character of the Nurse is that she has a strong character and that she is reliable, obliging, tactful and protective and wise.
Explanation: The Nurse is rightly upset, since Mercutio mocked her cruelly. After airing her anger, which reflects her strong character, she addresses Romeo and tells her that Juliet sent her to talk to him. This illustrates that she is obliging. She won't tell him what she asked her to tell him, which shows that she is reliable and tactful, but she warns Romeo: he should not promise her the moon, since she is too young, and he should not try to trick her, since no woman should be treated that way. This reflects that she is protective (of Juliet) and wise about some men's often questionable behavior.