Rosemary Palm is a 'Seamstress' in the city of Ankh-Morpork. A 'seamstress' does not make or mend clothes, however. A 'seamstress is a euphemism for a 'prostitute'. Rosy Palm takes her name from the British slang term for masturbation - 'visiting Mrs Palm and her five daughters'. Opportunities for lower-class girls to improve their stations were scarce in Ankh-Morpork, much like Victorian London after which the city seems to be patterned. Setting up some kind of shop required an investment that poor girls did not have. Marriage was popular, but no guarantee of improvement. The scion of some great Ankh family might come and carry off a young maiden to his mansion, but while some of the conventions of marriage might be observed, the actual legal marriage would not. So, the obvious career for an ambitious young woman of limited means was as a Lady of Negotiable Affection : minimal investment and the ability to charge whatever the traffic would bear. And the right traffic would bear some really impressive charges. Rosie was much like other little girls in her neighbourhood; maybe a little prettier, a bit cleverer, more inclined to do things her own way. She had what it took to succeed in Ankh-Morpork and elsewhere: looks, brains and ambition.
Amid the general unrest at the end of Lord Winder's tyranny, Rosie and other Seamstresses are at the center of the street-level rebellion leading to the Glorious Revolution of Treacle Mine Road since the Patrician of the day, Winder was as bad for her business as anyone else's. She is a member of the Revolutionary council and vetoes the fourth resolution of "Free Love" in the Republic's motto, resulting in the familiar "Truth, Justice, Freedom and Reasonably-Priced Love" instead. During the revolution she comes to the attention of Havelock Vetinari and Lady Roberta Meserole, two of the revolution's supporters among the political class. When Vetinari finally becomes the Patrician, he grants the Seamstresses' request for a Guild of their own, and Rosemary Palm becomes a member of the Patrician's council as the President of the Seamstresses' Guild.
From then on, no one calls her "Rosie" anymore, except those of long acquaintance. Mrs. Rosemary Palm is one of Ankh-Morpork's success stories, known far and wide; wealthy and the confidante of the powerful. (The honorific comes with with her position in the business; there is no Mr. Palm.) Her house in the "entertainment district" (formerly and rather more accurately known as 'The Whore Pits') is one of the city's great tourist attractions. When Granny Weatherwax and Nanny Ogg visit Ankh-Morpork in Maskerade they stay at Rosy's establishment (on the recommendation of 'Nev' Ogg) as does Carrot on first settling in Ankh-Morpork (in Guards! Guards!). Mrs Palm was considered almost a witch by Granny.