Topsy Lavish (née Turvy,) was in charge of the Royal Bank of Ankh-Morpork until her death. She has an appropriate maiden name in that 'topsy turvy' means in a state of confusion or upside down, much like the state of the bank she runs thanks to the predations of her in-laws. A former mistress of Joshua Lavish who later became his wife, she was left 50% of the Bank by her husband. The other 1% controlling share was left to her dog, Mr Fusspot. A very clever woman, she spent most the time that she is in charge of the Bank fending off her in-laws, the Lavishes, who wanted to run the place even further into the ground than it already was. Wary of assassination attempts, she spent all of her time in her suite at the Bank and had multiple crossbows pointed at the door, ready to be unleashed on a threatening visitor at any time.
She was partly responsible for Moist von Lipwig's ascension to her position after her death. She saw through Moist on his first visit to the Bank, recognizing him for the all-around liar and crook that he really was. Naturally, she liked him immensely, and when she finally did pass away, she left her 50% of the Bank shares to Mr Fusspot, making him the official Chairman - and then she left the dog to Moist with the warning that should anything happen to Mr. Fusspot, the assassin's guild had a contract out on him.
She tried to shoot Death when he showed up to collect her, saying "you can't blame a body for trying". She now rests at the Temple of Small Gods, as far away from the rest of the Lavishes as she can be.
It has been suggested that Topsy Lavish is a reference to Livia Drusilla, later Livia Augusta of the Roman Empire. Topsy replaced Joshua Lavish's first wife, following Livia's example with Emperor Octavian (later Augustus). Like Livia, Topsy is an expert at manipulation family she has married into and is also inmensely wealthy. However these comparisons can be made of a great number of powerful women during the Renaissance and the Lavish family resonate with the Medicis of Florence and the Borgias both powerful and manipulative families during the Renaissance in Italy and Europe. Certainly her step-son Cosmo Lavish who tries to emulate Vetinari draws his name from Cosimo Medici and her step-daughter Pucrezia is a clear take off on Lucrezia Borgia.