I think it's because she took so long to answer Juliet. She beat around the bush and asked "where is your mother" before telling Juliet about the plans.
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If you mean at the end when she sends the nurse away to drink to potion it's because
1. Friar Laurence told her to be all alone earlier in his instructions so that nobody other then himself and Romeo would know she's alive.
2. Juliet was still mad at the Nurse for saying that Romeo might as well be dead to her and she should just marry Paris.
She is teasing Juliet.
When the Nurse arrives, she doesn't tell Juliet the news right away. She is teasing Juliet, but she finally tells her the details of the plan.
Juliet I think both. Romeo is in a hurry to get married to Juliet and asks Friar Laurence to marry them shortly after they've met. Juliet, shows she's impatient when she is waiting for the Nurse to come back and give her news about the plans to get married to Romeo
Juliet says that if he is serious and plans to marry her, she will send a messenger to meet him at nine o'clock. This messenger will be the Nurse, of course. Romeo will then reveal whatever wedding plans he's made to her. Have you noticed how little wedding planning Juliet does in the play?
There are very few plans for the wedding of Romeo and Juliet - they get married in secret (only Friar Laurence and the Nurse know), so there can be no big event. The only real 'plan' is that the wedding will take place when Juliet visits Friar Laurence to give her confession.
Juliet sent the nurse to see Romeo about the wedding plans at 9 o'clock in the morning.
She is teasing Juliet.
Juliet asks the Nurse to find out Romeo's intentions regarding their relationship and marriage plans. She is eager to know if Romeo is serious about their love and if he plans to marry her.
The Nurse left at nine o'clock and it is twelve by the time she returns
When the Nurse arrives, she doesn't tell Juliet the news right away. She is teasing Juliet, but she finally tells her the details of the plan.
Because she is tired and she's ran out of breath
The nurse wants to talk to Romeo to deliver a message from Juliet or to discuss their plans for their relationship. She often acts as a messenger between the two lovers.
In Act 2, Scene 5, Juliet is waiting for the nurse to return with news from Romeo about their plans for their secret marriage. Juliet eagerly anticipates the nurse's return so she can hear what Romeo has arranged.
The nurse initially supports Romeo and Juliet's relationship and helps them in their plans to marry. However, she later experiences doubts and conflicting emotions as the situation becomes more complex and tragic.
Juliet I think both. Romeo is in a hurry to get married to Juliet and asks Friar Laurence to marry them shortly after they've met. Juliet, shows she's impatient when she is waiting for the Nurse to come back and give her news about the plans to get married to Romeo
Friar Laurence serves as a messenger between Romeo and Juliet. He helps them communicate and execute their secret plans to be together.
Juliet says that if he is serious and plans to marry her, she will send a messenger to meet him at nine o'clock. This messenger will be the Nurse, of course. Romeo will then reveal whatever wedding plans he's made to her. Have you noticed how little wedding planning Juliet does in the play?