Capricious--an adjective often applied to many a female character. When Juliet first learns that Romeo is a Montague, for instance, she certainly senses danger,
Prodigious birth of love it is to me,
That I must love a loathed enemy.
And, she bemoans that Romeo's name is Montague in the balcony of the next act; further, she cautions Romeo against his impetuous declaration of passion that same night, warning that it is "too rash, too unadvised, too sudden," yet before he departs she declares her love--"I will not fail...I love thy company" and she marries Romeo the next day.
Later, in Act IV, she rushes to Friar Laurence in her quandary of how to avoid marriage to Paris because she is, unbeknowst to her parents, already married. When the priest gives her the vial to drink, she is conflicting about doing so out of fear of not awakening from it, yet she capriciously downs it, anyway. Then, in Act V when she discovers that Romeo has killed himself for her, she kisses Romeo's lips, hoping that some poison "yet doth hang on them" so she can die "with a restorative."