The accused, Roshanjahan (24), was held last evening after a foul smell emanating from the bed in her house at Mustafabad in Gokulpuri led her family members to open the bedbox only to find the body of Ashna, they said.
The girl was reported missing on May 17 and the police were investigating the matter suspecting it to be a case of kidnapping, said a police officer.
The accused, mother of a six-month-old baby, was allegedly unhappy with the light banters between her husband and his sister-in-law Firdaus, and was depressed over it. The two sisters-in-law also had a heated argument a day before the minor girl went 'missing', the officer said.
Police suspected her statement since investigation and examination of CCTV footage of the area led to conclusion that the girl had not left her house at the time when the accused had claimed to have sent her for buying candies. Despite this they continued search for the girl considering it to be a case of kidnapping, the official said.
She was arrested today after she confessed her crime, added the officer.