Chowdhury was born in Denbigh, Wales. She was brought up in a Muslim family, along with five siblings, of whom she is the youngest. Shefali is of Bengali origin; her parents immigrated to England from Sylhet, Bangladesh in the 1980s, when many Bengalis migrated to the UK.
She plays Harry Potter's Yule Ball date, Parvati Patil, in Harry Potter and the Goblet of Fire. Daniel Radcliffe, who plays Harry Potter in the film, spoke at the launch of Goblet of Fire in London and said "I had a dance scene with Shefali. She was completely gorgeous."
Shefali landed the coveted role of Parvati Patil whilst she was still a student in her final year at Waverley School in Birmingham. She is currently completing her A Levels, in English Language, Literature, Sociology, and Religious Studies at The Sixth Form College, Solihull. Her studies coincide with shooting of the current installment of the Harry Potter series, Harry Potter and the Order of the Phoenix, where she reprises her role as Parvati Patil.
As of 2007, she is studying Photography in Birmingham, UK.