She played a slum girl in Nandanar (1942), while her role as a maid in Dasi Aparanji (1944) elevated her fame.
She later fell in love with Kothamangalam Subbu, another member of the Gemini staff who was a writer, actor, and director, and married him.
In 1945, Sundari Bai played the lead in Kannamma En Kadhali, a World War II film written by Subbu.
In 1947, Gemini produced the critically acclaimed but commercially unsuccessful Miss Malini, written and directed by Subbu, who also played the male lead.
She later went on to act in various films including Chandralekha, Samsaram, Moondru Pillaigal, Avvaiyar, Valliyin Selvan, Enga Veettu Mahalakshmi, Vanjikottai Valiban, Deivapiravi, Naan Kanda Sorgam, Padikkadha Medhai, Paadhai Theriyudhu Paar and Sila Nerangalil Sila Manithargal.