How does Shakespeare make an audience sympathize and empathize for Juliet?
Of the two lovers in Shakespeare's Romeo and Juliet, Juliet is not the initiator of the meeting, nor is it she who proposes marriage. In fact, she probably would not pursue the relationship with Romeo after he introduces himself and begs to touch her hands. For, when she is told who Romeo is, Juliet says, "Too early seen unknown, and known too late!" (1.5.148).
Always she extorts Romeo to be cautious: She backs away at the party from kissing him: "Saints do not move, though grant for prayer's sake" (1.5.110), and she is anxious about their relationship:
If they do see thee, they will murder thee.....
I would not for the world they saw thee here (2.2.74,78)
So frequently, Juliet cautions Romeo against his impetuous pursuit of her, telling him to go more slowly and not to swear his love by the moon or anything else:
...I have no joy of this contract tonight.
It is too rash, too unadvis'd, too sudden;
Too like the lightning, which doth cease to be
Ere one can say 'It lightens'....(2.2.122-125)
More than anyone else, Juliet seems the victim of fate. Happy with her new marriage, she soon learns that her beloved cousin has been slain by her tragic husband who has then been banished. Adding to her woes, Juliet soon encounters her mother who insists that she marry Paris. Even her Nurse encourages this marriage--knowing such a union would be bigomy--and Juliet feels isolated in her consternation. Placed into a terrible quandary, Juliet seeks the advice of Friar Laurence who has her drink a potion that will have the apparent effects of death in hopes of causing the parents to regret their decision. Hopefully, then, when she revives, they will be reconciled to her marriage to Romeo. But, before the young and delicate Juliet consumes this vial, she suffers tortuous fears that she will die, or if she does not, she will lose her mind when she awakens in the catacomb with skeletons, or she may not be able to breath in the tomb and die even if she does awaken.
Certainly, young Juliet endures many tribulations in the course of the three day romance with her Romeo. Her unfortunate awakening too late and finding her beloved dead is too cruel for such a young innocent. She is, indeed, one to whom great sympathy comes.
For me, personally, I feel sympathy for Juliet because she is the one who really gets the most pressure put on her during this play. She is the one who has to struggle more than anyone with conflicting pressures. I think that Shakespeare makes us feel for her through the situations he puts her in.
First of all, Juliet (unlike Romeo) is put in a bind between her parents and her love. Sure, we know the Montagues hate the Capulets, but we never see Romeo's parents telling him he has to marry someone. Juliet, by contrast, has to sit there and have her parents demanding that she should marry Paris even though she is completely in love with Romeo.
Second, we really see how badly Juliet's parents treat her. We see her being horribly berated by her father and mother for not wanting to marry Paris. When I, at least, read or hear those lines, my heart goes out to her for what her parents are doing to her.
So I think that Shakespeare makes us feel for her by putting her in a much more pressurized situation than anyone else in the play and by having her parents treat her as they do.