Natalie McDonald, 34, died in the blaze in Grangetown, near Middlesbrough, in the early hours of Wednesday, along with her niece Valentina Foster, seven.
Cleveland Police said a 48-year-old woman had been left in a critical condition in hospital and another three people had injuries that were not life-threatening.
Follow BBC Tees on X,, external Facebook, external, Nextdoor and Instagram, external and listen to Radio Tees on BBC Sounds.
Contact formContact formThis breaking news story is being updated and more details will be published shortly. Please refresh the page for the fullest version.
You can receive Breaking News on a smartphone or tablet via the BBC News App. You can also follow @BBCBreaking on X, external to get the latest alerts.
