A few years ago such a metamorphosis would have been impossible. Thami is black, and black girls seldom ventured in those days into the white world of ballroom dancing.
But in the new South Africa the old segregated white, coloured (mixed race) and black dance federations have been outlawed, and ballroom has caught the imagination of township kids. With girls like Thami clinching national titles only months after taking to the floor, the whites, who still call the tune, are uncomfortable.
"You should see where the black kids live," says Patricia Paleman, the only dance school teacher from the coloured township of Ennerdale, south of Johannesburg, to recruit kids from the neighbouring black squatter camp of Orange Farm.
Coloured boys are shy of dancing, so there may be a degree of self- interest in her black recruitment drive. But her motivation runs deeper. "The black kids cannot even afford the bus fare to get here," she says. "But they have such a talent to dance. At first they had no experience of the dance syllabus but now they are taking first, first, first."
As small girls in green mini-dresses and boys in dinner suits waltz by, she says the man responsible for the new championship standards at the Ennerdale Academy of Dance is Paul Kgole, one of a handful of blacks to beat the old apartheid restrictions to qualify as a ballroom teacher. When Soweto was torn by violence in the mid-1970s the teenage Paul still managed to fit in his dance lessons - between spells in jail.
He now teaches competition basics for free at Mrs Paleman's club. A new, racially integrated, amateur dancing federation, Fedansa, has been credited for the explosion in township interest. But Mr Kgole claims the trend is under way in spite of, rather than because of, the federation.
The board's executive remains all white. The old guard of dance, like that of rugby, is resisting black pressure for change. Fedansa refuses to hold competitions in townships, so that most of the contests remain segregated except for a few, big events.
Fedansa has yet to set up a scholarship or a development programme for blacks, and while many white girls can afford pounds 200 glittering ballgowns, Mr Kgole's students have been threatened on occasions with disqualification because their homemade costumes failed to meet the strict dress regulations.
Mr Kgole's 15-year-old nephew, Keabetsoe Ramoshebi, from Soweto, is already winning dance championships. He says the whites who claim they are too scared to come to township competitions are making excuses. He dances at Mrs Paleman's because Soweto has no proper dance schools. At a recent meeting of Fedansa he said the executive should be multiracial and the funds directed at areas that needed them most: "It did not go down well."
South Africa's ballrooms continue to mirror a fractured society. The white elite shrinks from contact with coloureds and blacks, while coloureds often refuse to have blacks as partners.
Mrs Paleman's club is unusual. For years she has ventured into black areas to conduct workshops with the kids. "She is the only sympathetic coloured I know," says Mr Kgole. But kids, he says, mix well at competitions, whatever their colour. "The white kids all ask my advice and are keen to find out how I became the only black judge. It's the adults who have a problem."