Juliet and her Nurse have been together since Juliet was born. She was the one who nursed Juliet as a baby, and she was with her far more often than Juliet's mother was.
Romeo trusts Friar Laurence in the same way that Juliet trusts the nurse. Friar Laurence is a confidant to Romeo because he is the person Romeo goes to for help. The nurse is a friend to Juliet because she helps Juliet meet up with Romeo.
