Juliet, like Romeo, makes the transition from an innocent adolescent to responsible adult during the course of the play. In Juliet's case, however, there is a heightened sense that she has been forced to mature too quickly. The emphasis throughout the play on Juliet's youth, despite her growing maturity, establishes her as a tragic heroine.
Juliet is presented as quiet and obedient; however, she possesses an inner strength that enables her to have maturity beyond her years. When her mother suggests that she marry Paris because Paris is rich and good looking, Juliet responds: "I'll look to like, if looking liking move" (I.3.97).
When she meets and falls in love with Romeo, she is prepared to defy her parents and marry Romeo in secret. In Act III, Scene 5, Capulet demands his right as her father to marry her to Paris, threatening her with disinheritance and public shame.
Juliet, however, is resolute in her decision to die rather than enter into a false marriage: "If all else fail, myself have power to die"(III.5.244). At this point, when Juliet is most isolated from her family, even the Nurse betrays Juliet's trust by advising her to forget Romeo and comply with her father's wishes.
In her relationship with Romeo, Juliet is loving, witty, loyal, and strong. When Romeo and Juliet kiss at the feast, Juliet teases Romeo for using the popular imagery of love poetry to express his feelings and for kissing according to convention rather than from the heart: "You kiss by th' book" (I.5.110). This establishes a pattern for their relationship in which Juliet displays greater maturity, particularly in moments of great emotional intensity.
In the balcony scene of Act II, Scene 2, Juliet is aware of the foolhardiness of their love: "It is too rash, too unadvis'd, too sudden." This sense of rushing headlong accurately characterizes their love, yet despite her premonition, Juliet is the one who suggests later in the scene that they marry. Act III, Scene 2, marks Juliet's move toward sexual and emotional maturity when she anticipates the consummation of her marriage to Romeo. The lyrical language Juliet employs as she waits impatiently for the night to come underscores the intensity of her feelings:
Spread thy close curtain, love-performing night,
That runaway eyes may wink, and Romeo
Leap to these arms untalk'd of and unseen.
The news of Tybalt's death initially produces conflicting feelings for Juliet because she's torn between her love for her husband and the loyalty she feels for Tybalt, her slain cousin: "Shall I speak ill of him that is my husband?" (III.2.98). Juliet's love for Romeo soon resolves the conflict:
My husband lives, that Tybalt would have slain,
And Tybalt's dead, that would have slain my husband.
All this is comfort.
Juliet's decision in Act IV to take the Friar's potion rather than enter into a bigamous marriage with Paris increases Juliet's stature as a tragic heroine. She reflects on the plan but prepares to face the dangers involved bravely: "My dismal scene I needs must act alone."