The other female suicide bomber was identified last week
Russian officials have confirmed the identity of the second suicide bomber to attack the Moscow metro, a 28-year-old woman from Dagestan.
Mariam Sharipova is the wife of Islamist rebel commander Magomedali Vagapov, the officials said.
On Monday the Novaya Gazeta newspaper quoted Sharipova's father as saying he recognised her from a photo of the bomber circulated on the internet.
The blasts last week killed 40 people. The other bomber has been identified.
A Chechen militant leader, Doku Umarov, has said he ordered the 29 March rush-hour bombings, which also injured more than 80 people, most of whom are still in hospital.
Last week the Russian authorities identified the other suicide bomber as a 17-year-old girl from Dagestan - Dzhennet Abdurakhmanova. She was believed to be the widow of a senior Caucasus militant killed by Russian security forces in December.
Dagestan, like neighbouring Chechnya, is struggling to quell militant violence.
Sharipova's father Rasul Magomedov told Novaya Gazeta he had recognised his daughter by a red scarf she was wearing in the internet photo.
His daughter had been teaching computer science since 2006 at a school in the village of Balakhani in Dagestan, he said. She lived with her parents, both of whom are teachers in Balakhani.
Mr Magomedov said Mariam had gone shopping with her mother in the Dagestani capital Makhachkala on Sunday 28 March - the day before the Moscow attacks.
That Sunday afternoon she rang her mother to say she would be visiting a friend and would return home by herself, but she then disappeared.