Mother Zannatul Ferdous also died two days after her little son Rushdi's tragic death in a building fire in city's New Eskaton area.
She succumbed to her burn injuries at the Sheikh Hasina National Burn and Plastic Surgery Institute around 9:35am on Sunday, bringing the tally from the fire to four.
The institute residential doctor Partha Shankar Pal confirmed the matter, adding that she suffered 95 percent burn on her body.
Condition of the woman's husband Shahidul Kirmani, who also received serious burn injuries in the fire, is critical, and sent him to Intensive Care Unit (ICU) today.
A five-storey building at Dilu Road caught a devastating fire early Friday. After the fire, three charred bodies, including of four-year-old Rushdi, were recovered, and several injured rescued.