A 41-year-old woman has been arrested on suspicion of the murder of Ayesha Ali.
Ayesha, eight, was found with a head injury on August 29 at her home in Bedwell Court, Broomfield Road, Chadwell Heath.
Ambulances had been called to the flat to reports of an injured child about 11.40am, but Ayesha was pronounced dead at the scene.
Her mother Polly Chowdhury, 34, was arrested at the time and has been charged with her murder. She will appear at the Old Bailey in November.
A second woman was arrested on Tuesday and remains in police custody at a north-east London police station.
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