While still in High School at Performing Arts NYC, Franceschi was cast as one of 10 dancers from the east coast joining 10 from the West Coast in the 1979 film Grease. She lied about her age which was under 18, so subsequently got a fake birth certificate in order to be hired. She was expelled from the High School of Performing Arts for her role in Grease, as professional performers were not permitted to attend the school.   She then accepted a scholarship to SAB, and completed her education at PCS. 
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During her time at SAB, she was cast as Hilary Van Doren in the movie Fame, directed by Alan Parker. During the filming of Fame, Mr George Balanchine came into class to choose his new dancers for the New York City Ballet. Antonia was fortunately in this class but immediately after it had to run to the set to shoot her most dramatic scene and didn’t know she had been chosen until the very end of that working day. Being chosen by Balanchine was a joyous pinnacle of her life. She turned down a lucrative Hollywood contract for more films and accepted her dream position a contract with the NYCB. While an apprentice, she was invited to join Makarova and Company performing at The Uris Theatre where she was coached by Natasha Makarova herself and danced Bach Sonata by Maurice Bejart with Anthony Dowell.  When Natasha sustained an injury, Antonia learned the pas de deux overnight, coached by Natasha and Madame Dobryavitch. Her performance was an enormous success and Clive Barnes wrote in the NY Post “Here is a star to watch.” That October, 1981, as Fame premiered, she became a full member of the NYCB for over 11 years where she went on to dance in over 90 of Balanchine Ballets as well as most of Robbins repertoire.  
 
She moved to London shortly thereafter and, along with winning The Time Out “Outstanding Achievement in Dance" Award, she was a guest artist performing in The Royal Opera House, Tate Modern, Sadler’s Wells, The Royal Albert Hall, The Queen Elizabeth Hall, as well as in Paris, Italy, Portugal, Greece, and Poland. 
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She has had works created for her by George Balanchine, Jerome Robbins, Lar Lubovitch, Peter Martins, Wayne McGregor, Mark Baldwin, Michael Clark, Arlene Phillips, Karole Armitage, Cathy Marsden, Anthony Van Laast among others.
 
Antonia made several films as a dancer which she continues to find hugely rewarding and continues to perform on stage. She recently performed a duet at the 92 Y in celebration of her teacher Margaret Craske, and filmed a new dance film Dinner With Taglioni in London, to be released later this year, as Taglioni, with the brilliant film makers Jess and Morgs Films.