Three-year-old Maheen Shakoor has lost her fight for life in hospital following the house fire which killed her mother and four siblings.
The death leaves Dr Abdul Shakoor as the only survivor of the fire, thought to be arson, which broke out in the early hours of Monday morning.
Dr Shakoor is still recovering in the burns unit at Broomfield Hospital, Chelmsford.
His wife Sabah Usmani, sons Sohaib, 11, Muneeb, 9 and Rayyan, 6 as well as daughter Hira, 13, all died.
Mid Essex Hospital Trust said in a statement: "Trust staff and the specialist care team from the St Andrew's Burns Centre offer their sincere condolences."
A book of condolences was opened yesterday at Harlow's Civic Centre.
The investigation into the fire continues.
