Until act 3, scene 1 of Shakespeare's Romeo and Juliet, when Romeo kills Tybalt and the Prince exiles Romeo from Verona, Juliet is no more practical than Romeo is.
Juliet seems to be more practical than Romeo because she behaves in a much less impetuous and emotional way than Romeo does.
In act 1, scene 3, for example, Juliet's mother, Lady Capulet, tells Juliet that Paris is interested in marrying her, but rather than jump at the opportunity, Juliet takes a much more measured approach.
LADY CAPULET. Speak briefly, can you like of Paris’ love?
JULIET. I'll look to like, if looking liking move;
But no more deep will I endart mine eye
Than your consent gives strength to make it fly. (1.3.100-103)
At about the same time that Juliet is speaking with her mother about Paris, Romeo is lovesick over "the fair Rosaline."
ROMEO. Why, such is love's transgression.
Griefs of mine own lie heavy in my breast...
Love is a smoke rais'd with the fume of sighs;(190)
Being purg'd, a fire sparkling in lovers’ eyes;
Being vex'd, a sea nourish'd with lovers’ tears.
What is it else? A madness most discreet,
A choking gall, and a preserving sweet. (1.1.185-194)
Romeo speaks in rhapsodic, poetic terms, whereas Juliet's language is more straightforward and grounded.
ROMEO. O, she doth teach the torches to burn bright!
It seems she hangs upon the cheek of night
Like a rich jewel in an Ethiop's ear—
Beauty too rich for use, for earth too dear!
So shows a snowy dove trooping with crows
As yonder lady o'er her fellows shows.
The measure done, I'll watch her place of stand
And, touching hers, make blessed my rude hand.
Did my heart love till now? Forswear it, sight!
For I ne'er saw true beauty till this night...
JULIET. You kiss by th’ book. (1.5.46-55, 116)
This doesn't mean, however, that Juliet is more practical than Romeo. Juliet falls in love with Romeo at first sight, as does he fall in love with her.
In act 2, scene 2, the "balcony scene," Juliet seems more practical because she warns Romeo about Tybalt and others; "if they do see thee, they will murder thee" (2.2.74). Could Juliet not simply be thrilled at the prospect of being discovered and enthralled with the romantic notion of her brave lover, Romeo, fighting for her love?
Juliet also express concerns that their relationship might be moving too fast towards marriage.
JULIET. It is too rash, too unadvis'd, too sudden;
Too like the lightning, which doth cease to be(125)
Ere one can say ‘It lightens.’ (2.2.124-126)
It was Juliet, however, who proposed marriage to Romeo, even though she first met and fell in love with him at first sight just a few minutes before.
Juliet is no less caught up in the idea of love and no less fixated on the idea of marriage than is Romeo. Marrying Romeo is hardly practical, in that she prefers Romeo to Paris, who is a wealthier and better-situated young man than Romeo. It's not at all practical for Juliet to marry Romeo and defy her parents, who can disown her and send her penniless into the streets, as her father threatens to do when she refuses to marry Paris in act 3, scene 5.
Juliet changes after Romeo kills Tybalt and is exiled from Verona, but Romeo doesn't change at all. As Romeo and Juliet's situation becomes more desperate, Juliet's strength of character emerges, whereas Romeo simply falls apart emotionally.
Romeo rants and raves about his banishment. He makes a pitiful spectacle of himself by throwing himself on the floor in Friar Laurence's cell and threatening to kill himself. He won't listen to Friar Laurence's advice.
ROMEO. ...Hang up philosophy!
Unless philosophy can make a Juliet,
Displant a town, reverse a prince's doom,
It helps not, it prevails not. Talk no more. (3.3.58-61)
In contrast, Juliet goes to Friar Laurence for practical advice on how to resolve the situation. She, too, threatens to kill herself but only if a solution can't be found.
JULIET. Tell me not, friar, that thou hear'st of this,
Unless thou tell me how I may prevent it.
If in thy wisdom thou canst give no help,
Do thou but call my resolution wise
And with this knife I'll help it presently. (4.1.51-55)
Ultimately, however, both Romeo and Juliet revert to their dramatic, romantic, impractical selves and kill themselves, each for the love of the other.