How does the Nurse influence Romeo and/or Juliet?

The Nurse is an interesting character. Some of her lines indicate a total disapproval of Romeo and Juliet’s disobedience, and she might be viewed as being somewhat against their relationship. That being said, the Nurse is incredibly devoted to Juliet and would do anything to see her be happy. After the Nurse’s own daughter, Susan, died in infancy, she became a wet nurse to baby Juliet. As someone who has shared an incredibly close relationship with the young woman, the Nurse is Juliet’s confidant and the member of the household with whom Juliet is closest. Her influence on Romeo and Juliet's relationship is shown as she passes information along to both of them at pivotal moments throughout the play.
Her support was vital to their plans to elope, and it is unlikely that they would have been able to meet each other in secret without the Nurse's help. Later, once Juliet learns of her impending marriage to Paris, she rebukes the Nurse for her suggestion that she proceed with the marriage. The Nurse argues that Juliet should marry Paris because Romeo has been exiled, and it is unlikely that they will ever see each other again. Juliet refuses to fully trust the Nurse with her secrets after this rift, which is unfortunate. If the Nurse had been aware of Juliet’s plan to take the sleeping potion, she perhaps could have provided useful information to Romeo before the final tragedy of the play took place.