The court ruled that the suspect can be detained until April 29, to allow time for the investigation. The suspect did not protest the arrest.
The woman, who is reportedly mentally unstable, may be held in the psychiatric facility of the Butyrskaya pretrial prison, a police source told RIA Novosti.
"Due to the detainee possibly requiring psychiatric help, following her arrest she may be placed in the Federal Penitentiary Service's second pretrial detention center in Moscow, where a psychiatric ward is located," the source said.
According to the Russian Federal Migration Service, the nanny was a migrant from Uzbekistan and worked in Russia without a work permit. The motive for the attack is still unknown. Previously, the woman claimed that the attack was motivated by her partner's cheating, but failed to link the murder to the cheating allegations.