when she was alone in her house in South Delhi's Vasant Vihar area.
The incident took place last evening inside an army servant quarter when the 15-month-old girl's mother, who is a domestic help, had gone to visit a relative who lives nearby, police said.
When her mother returned, she found the child bleeding, the police said.
Police have detained two persons, including the victim's juvenile cousin, for questioning.
The child has been admitted to Safdarjung hospital where her condition is stated to be stable.