Three-year-old Maheen Shakoor has died as a result of the house fire, which claimed the lives of her mother and four siblings, a hospital spokesperson has confirmed.
The toddler's mum Sabah Usmani, brothers Sohaib, 11, and Rayyan, six, and her 12-year-old sister Hira, died in their end-of-terrace house in Barn Mead, Harlow, Essex in the early hours of Monday.
Maheen's nine-year-old brother Muneeb died later in hospital. Her father Dr Abdul Shakoor is continuing to receive treatment in hospital, while police continue to investigate the cause of the blaze.
A spokesman for the Princess Alexandra Hospital, where Dr Shakoor worked and where Maheen was initially taken, has said:
Police investigating the blaze say they are not ruling any possibility out and are continuing to investigate whether it was an arson attack.
However, early results suggest the fire started in the lounge at the rear of the house and no accelerant, such as petrol, was used.