Fatima was born into the Jinnah family on 31 July 1893, the youngest of seven children to Jinnahbhai Poonja and his wife Mithibai, in Kathiawar, Gujarat, during the Bombay Presidency in British India. Fatima had six siblings: Muhammad Ali, Ahmad Ali, Bunde Ali, Rahmat Ali, Maryam, and Shireen Jinnah. Of her siblings she was the closest to Muhammad Ali Jinnah who became her guardian upon the death of their father in 1901. She joined the Bandra Convent in Bombay in 1902. In 1919, she was admitted to the highly competitive University of Calcutta where she attended the Dr. R. Ahmed Dental College. After she graduated, she opened a dental clinic in Bombay in 1923.