T'malia
One of the few women to achieve high office in the Assassins' Guild, Lady T'malia also teaches Political Expediency. If you wish to enjoy a long life, do not have dinner with her, as it is generally believed that the jewellery of one hand alone contains enough poison to inhume a small town. See here: [1]
She remains stunningly beautiful, but these days with the sort of calculated beauty that is achieved every morning by three hours hard work on the part of a skilled team of artists, manicurists, plasterers, corsetières and dressmakers. As she moves, she is accompanied by the faint creaking and squeaking of whalebone under near-terminal stress.
Fast learners in her classes don't watch her figure, they watch her hands. She is currently housemistress of Scorpion House.
In a Roundworld adaptation of Pyramids, she could be played by Joan Collins, who in several senses has been waiting all her life for a role she was born for.