The police said that the accused woman lived on the second floor of a rented accommodation.
It is suspected that the accused killed the child by banging his head on the floor. The child used to play with the accused woman's children, the police said.
The accused woman had an argument with the victim's mother a few days back, they said.
The child was rushed to a hospital where he was declared brought dead, the police said, adding the woman was arrested.
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.