Narasamma had accidentally slipped into the drain. Her body was later recovered at some distance from the slum where her family resides.
The family hailed from a northern district of Karnataka and they worked as construction labourers in the city.
Meanwhile, the city civic body Bruhat Bengaluru Mahanagara Palike along with the National Disaster Response Force and the State Disaster Response Force fished out the body of 22-year-old Pushpa from a storm-water drain at Kumbalgodu this morning.
Pushpa and her mother Ningamma were washed away in the storm water drain following heavy rains in the city on Friday night. Officials involved in search operations said efforts were on to recover Ningamma's body.
The 10 deaths in the past 15 days in mishaps due to potholes and incessant rains have triggered a political slugfest between ruling the Congress and the BJP.
Speaking to reporters in Mysuru, Chief Minister Siddaramaiah hit out at the BJP for politicising the issue. He said his government has taken up the repair work and clearance of the 850-km storm water drain network in the city by allocating Rs 800 crore.
"No government including the BJP has done it in the past. Now they are playing politics over deaths," he said.
About 46 days in the last two months gauged heavy rains, he said, adding "our drainage system and storm water drains do not have the capacity to bear it".
BJP state president Yeddyurappa who visited the rain affected areas yesterday had squarely blamed Siddaramaiah for the deaths.
Reports quoting Met department officials suggested the city has witnessed about 1,620 mm of rainfall this year so far, breaking the record of about 1,600 mm of precipitation in 2005.
The department has predicted generally cloudy sky in and around Bengaluru, one or two spells of rain and heavy showers in some areas in the next 48 hours.
Meanwhile, there were reports of heavy rains from different parts of the state. In neighbouring Ramanagara, a 35-year-old man was washed away as he slipped into an overflowing pit.