The Nurse's key function within the play is to act as a go-between for Romeo and Juliet, and is the only other character besides Friar Laurence to know of their wedding. The Nurse, despite being a servant in the Capulet household, has a role equivalent to that of Juliet's mother and regards Juliet as her own daughter.
The Nurse's relationship with Juliet focuses attention on Juliet's age. In Juliet's first scene, the Nurse repeatedly asserts that Juliet has not yet had her 14th birthday. In contrast to Juliet's youth, the Nurse is old and enjoys complaining about her aches and pains. Juliet's frustration at having to rely upon the Nurse as her messenger is used to comic effect in Act II, Scene 5, when Juliet is forced to listen to the Nurse's ailments while trying to coax from her the news of her wedding plans:
The Nurse, like Mercutio, loves to talk at length. She often repeats herself, and her bawdy references to the sexual aspect of love set the idealistic love of Romeo and Juliet apart from the love described by other characters in the play. The Nurse doesn't share Juliet's idea of love; for her, love is a temporary and physical relationship, so she can't understand the intense and spiritual love Romeo and Juliet share. When the Nurse brings Juliet news of Romeo's wedding arrangements, she focuses on the pleasures of Juliet's wedding night, "I am the drudge, and toil in your delight, / But you shall bear the burden soon at night" (II.5.75-76).
This clash in outlook manifests itself when she advises Juliet to forget the banished Romeo and marry Paris, betraying Juliet's trust by advocating a false marriage:
I think it best you married with the County.
O, he's a lovely gentleman.
Romeo's a dishclout to him.
Juliet can't believe that the Nurse offers such a course of action after she praised Romeo and helped bring the couple together. The Nurse is ultimately subject to the whims of society. Her social position places her in the serving class — she is not empowered to create change around her. Her maternal instinct toward Juliet buoys her to aid Juliet in marrying Romeo; however, when Capulet becomes enraged, the Nurse retreats quickly into submission and urges Juliet to forget Romeo.