NDRF personnel from the nearby Changsari camp rushed to the spot and recovered their bodies from under a stone.
The woman has been identified as Sumita Khaklary and the child as Rashmi Khaklary.
The landslide occurred following heavy rainfall for the past few days.
A district official said that construction was banned in Kalipahar area but encroachment was continuing.
The matter would be investigated, he said.