Goar Davtyan, 67, was arrested Friday night and charged with felony hit-and-run and felony vehicular manslaughter, Glendale police said.
Her daughter, Alina Davtyan, 41, of Glendale was arrested for accessory to a crime and filing a false insurance claim.
The hit-and-run occurred on the night of April 16, when an 81-year-old man was crossing Broadway at Belmont Street and was hit by a white sedan. Martiros Arutyunyan of Glendale suffered head injuries and later died at the hospital.
Police said they had identified Davtyan as a person of interest early in the investigation, but waited to gather more evidence before making the arrest.
The city of Glendale had announced a $50,000 reward in connection to the case, but it was not immediately clear if the reward would be claimed.