Why is Juliet at first cautious about making promises to Romeo (Scene 2, lines 116-120)

Romeo And Juliet is a famous tragedy (type of drama) written by the most famous icon in literature, William Shakespeare. This is all about the two young lovers and their feuding families, which later on reconciled after the two young lovers' death.

This drama is composed of many scenes. In scene 2, between the lines of 116-120, Juliet was first cautious about making promises to Romeo because their romance (their love) was too sudden.