"She was taken to King Xerxes in the royal residence in the tenth month, the month of Tebeth, in the seventh year of his reign." NIV translation
Esther's turn came and if we look behind the scenes we can see that God was still in control. It was the tenth month and the number ten throughout the Bible tells of earthly completion. It was the seventh year and seven is the number of spiritual completion. God's divine will is going to meet with earthly circumstances at this time.
"Now the king was attracted to Esther more than to any of the other women, and she won his favor and approval more than any of the other virgins. So he set a royal crown on her head and made her queen instead of Vashti." NIV translation
God continued to work and Esther was favored by the king. You can almost feel that God has a reason for this although we don't see it yet.
That is true in our daily lives as God is constantly in control and working but we don't always see His purpose. As His children we can be confident that He is looking out for our best interests.
"And the king gave a great banquet, Esther's banquet, for all his nobles and officials. He proclaimed a holiday throughout the provinces and distributed gifts with royal liberality." NIV translation
After Esther was chosen, the king threw a big banquet to show her off. He celebrated by declaring a holiday.
"When the virgins were assembled a second time, Mordecai was sitting at the king's gate. But Esther had kept secret her family background and nationality just as Mordecai had told her to do, for she continued to follow Mordecai's instructions as she had done when he was bringing her up." NIV translation
Even after she became queen, Esther humbled herself and continued to listen to Mordecai. She still kept the fact that she was a Jew hidden from the king. Meanwhile, Mordecai was promoted from a servant of the king to a judge (Esther probably put in a good word for him with the king). We can tell that by the fact that we are told that he was sitting at the king's gate (that was where the judges held court).