From Monkey Island wiki
The Harbor Mistress is a thoroughly unpleasant figure and the head of the Mêlée Island shipyard in the fourth game. Guybrush Threepwood is able to procure a boat, the Dainty Lady, from her harbour only after he gets the Gubernatorial Seal of Mêlée Island from Elaine. She doesn't care to deal with Guybrush when they first meet and doesn't really warm up to him at any point.
A nude portrait of her is on display at the Scumm Bar. Guybrush comments on it, "The human body is a beautiful thing... most of the time, eww." If the player questions the Harbor Mistress she says the artist had an obsession with wax, leading to the conclusion that Meathook was responsible for the picture. She also insists that she was not "naked" but simply "artistically posed".
She is voiced by Lauri Johnson.