Police charged 22-year-old Lisette Capellan with second-degree murder on Wednesday, nearly two weeks after her husband was indicted on the same charge.
Investigators say 41-year-old Michael Aviles and his wife brought the severely injured baby to a hospital early on Jan. 16.
She died later that day.
An autopsy revealed that the baby suffered skull and rib fractures.
Capellan's lawyer told the Journal News that he had just learned of the arrest and didn't know the details.