Because she had a bad dream(nightmare) about Jesus. Pilate would have been wise to follow her advice.

Source: Matthew 27:19

Paul received a call from God to go to Macedonia in a dream or vision. What was the specific vision?

A man of Macedonia appeared to Paul in a dream and asked him to come help them. Macedonia is located in present day Greece.

Source: Acts 16:9

God appeared to the young King Solomon in a dream and offered him whatever he asked. What did the young King ask of God?

Solomon asked for a heart of understanding and wisdom to rule God’s people well. God was so impressed with his selfless request that he gave him much more than he asked.

Source: 1^st Kings 3:5-15

King David planned to build a temple to God. God told me in a dream to tell David no, I went and did what God told me. King David accepted this. Who am I?

My name is Nathan.  I served King David as prophet after Samuel.

Source: 2^nd Samuel 7

In Acts 2:17 it says “ And it shall come to pass in the last days, saith God, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams.”  This is a quote from the Old Testament which book are they quoting?

It is in the book of Joel.  Joel 2:28.

Source: Joel 2:28

God provided a test for dream interpreters in Deuteronomy 13. When did he say the Israelite’s were not to follow a prophet or interpreter of dreams?