Act 3, Scene 2, Lines 101-104 Juliet: "Shall I speak ill of him that is my husband? Ah, poor my lord, what tongue shall smooth the name, When I, thy three-hours wife, have mangled it? But, wherefore, villain didst thou kill my cousin?
Juliet has learned that her husband (Romeo) killed Tybalt and is conflicted because she doesn't know who to support. Juliet loves Romeo and wants to support him because he is her husband and knows that Tybalt would have killed him. However, Juliet wants to be on Tybalt's side because he is her cousin and he has been murdered. Although, Juliet was struggling, she eventually decided to support her husband Romeo.
Act 3, Scene 1, Lines 78-80, 86-87 Tybalt: "I am for you. (drawing)" Romeo: Gentle Mercutio, put thy rapier up." Mercutio: "Come, sir, your passado. (They Fight)" Mercutio: "I am hurt. A plague o' both your houses! I am sped."
Tybalt, Mercutio, Benvolio, and Romeo see each other on the street and the atmosphere becomes tense since Tybalt is a Capulet, makes fun of Romeo, a Montague, and starts to challenge them to a fight. Eventually, this becomes violent and Mercutio is wounded. This fight leads to the death of Mercutio and Tybalt, which is the climax, so it propels the plot drastically.
In order for Romeo and Juliet to be together, Friar Lawrence crated a plan that requires Juliet to die temporarily and have Romeo save her when she wakes up, so they could run away together. Juliet is having doubts about whether or not to drink the mixture. Therefore, she is having an internal battle with her thoughts.
Act 4, Scene 3, Lines 22-23, 25-28 Juliet: "What if this mixture do not work at all? Shall I be married then to-morrow morning?..." Juliet: "What if it be a poison, which the friar subtly hath minist'red to have e dead, Lest in this marriage he should be dishonour'd Because he married me to Before Romeo?..."