How would you describe the nurse in Romeo and Juliet?

Certainly, the nurse is genuinely devoted to Juliet.  Early on, when Juliet's mother approaches her regarding the County Paris's suit, the nurse recounts Juliet's early years, remembering exactly when Juliet was weaned, when she could stand on her own, and so forth.  The nurse is more loving -- much more loving -- to Juliet than her own mother is.  

Further, she helps to arrange Juliet's secret marriage to Romeo, seeming to care most for...

Certainly, the nurse is genuinely devoted to Juliet.  Early on, when Juliet's mother approaches her regarding the County Paris's suit, the nurse recounts Juliet's early years, remembering exactly when Juliet was weaned, when she could stand on her own, and so forth.  The nurse is more loving -- much more loving -- to Juliet than her own mother is.  

Further, she helps to arrange Juliet's secret marriage to Romeo, seeming to care most for the girl's happiness.  She even helpfully carries the ladder to place against the house so that Romeo can climb up to Juliet's bedroom on the night of their wedding!  The next morning, the nurse comes to warn Juliet that her mother is awake and on her way to Juliet's bedroom.  She is sincere, loyal, warm, loving, and even sort of funny with her bawdy jokes and puns.

She seems to lose Juliet's favor when she agrees with her parents that Juliet should marry the County Paris.  Once she sees, I think, how strongly in favor of the match her parents are, weighed against Juliet's first marriage to a young man who her parents hate and who has been banished from Verona, she speaks her mind truthfully to Juliet -- a sign, I believe, of her continued loyalty.  She just wants her to be happy, and she doesn't see how that is possible with a marriage to the hated and exiled Romeo.  Ultimately, she seems to look out for Juliet as best she can, even when her opinion differs from her charge's.