Laeral Silverhand is the Open Lord (ruler) of Waterdeep. She wears a green cloak and her silver hair goes all the way to the floor. Laeral told Diath that she was going to help him when he was imprisoned. She said that she appreciated that Diath had rid the city of the Xanathar.  She later disguised herself as Talastin, infiltrated Jarlaxle's ship, and helped the heroes rescue their owlbear. 
Waterdeep: Dragon Heist
Anamanue Laeral Silverhand is the fifth of seven daughters of the goddess Mystra. In the past, she ruled the kingdom of Stornanter and was married to an adventurer named Khelben Arunsun, who would become the Blackstaff, the Lord Mage of Waterdeep. He died, and now Laeral rules Waterdeep after Dagult Neverember was ousted as the Open Lord.