Sutha Sivanantham, 35 of Monarch Parade, Mitcham has been charged with murder.
She will appear via video link at Wimbledon Magistrates’ Court on Friday, 11 September.
Police were called to an address on Monarch Parade in Mitcham at 16:00hrs on Tuesday, 30 June to a report of two people injured.
Officers attended and found a woman and a girl suffering from knife wounds.
A five-year-old girl was taken to hospital by London Ambulance Service where she was subsequently pronounced dead.
The victim has been formally identified as Sayagi Sivanantham.
A post-mortem examination held at Great Ormond Street Children’s Hospital on Friday, 3 July, gave cause of death as stab injuries.