Final answer:
Lady Capulet's reaction to the sudden change in wedding plans is not detailed in the play, but she likely acquiesces to her husband's decision.
Step-by-step explanation:
In Act 4 of Shakespeare's Romeo and Juliet, Lady Capulet's reaction to the altered wedding plans, which have been moved up by Lord Capulet without consulting her or Juliet, is not explicitly shown in detail. The focus of the play at this point is more on Lord Capulet and Juliet's interactions. From the dynamics that unfold, we can deduce that Lady Capulet, being accustomed to following her husband's lead, likely acquiesces to the changed plans. The play does not spend much time on her perspective, instead demonstrating how the hastened wedding becomes a new source of pressure for Juliet and directly impacts the tragic events at the end of the play.