The 84-year old had been suffering from various ailments for some time.
She was admitted to the Labaid Hospital on Thursday where she had been kept at the ICU.
"There's an infection in her kidney," hospital doctor Prof Baren Chakraborty told bdnews24.com. "She had a dialysis six months ago."
Her condition was improving, the doctor said.
Ayesha Foyez is the mother of Humayun Ahmed, noted writer, and teacher Prof Zafar Iqbal and cartoonist Ahsan Habib.
She was born on Mar 23, 1930 at Barhatta's Koitali village to Abul Hossain and Khairun Nesa.
Her husband Faizur Rahman was a police officer, who was a Liberation War martyr.