Juliet is definitely more practical than Romeo. She is still young, but she tends to think of the consequences of actions more.
For example, in Act II, Scene 2, when Romeo sneaks into her backyard, she warns him that if he is found he will be killed. Romeo does not seem to care.
If they do see thee, they will murder thee. (enotes etext p. 40)
In Act III, Scene 5, she also comments to Romeo that she has heard a nightingale, meaning it is daylight now and Romeo needs to leave. Romeo again dismisses her idea.
Wilt thou be gone? It is not yet near day.
It was the nightingale, and not the lark,
That pierc'd the fearful hollow of thine ear.
Nightly she sings on yon pomegranate tree.
Believe me, love, it was the nightingale.(5) (p. 78)
Also, let it be noted that while Romeo killed himself when he thought Juliet was dead, Juliet actually faked her death first and only killed herself in response to Romeo’s suicide in Act V, Scene 3.
What's here? A cup, clos'd in my true love's hand?
Poison, I see, hath been his timeless end.
O churl! drunk all, and left no friendly drop
To help me after? I will kiss thy lips.
Haply some poison yet doth hang on them(170)
To make me die with a restorative. (p. 111)