Officers were called to a property on Dale Street, New Marske, on the morning of Tuesday 10th November, to a report of an injured child.
The girl, who can now be named as Grace Thorpe from New Marske, was taken to the Royal Victoria Infirmary for treatment, where she sadly passed away today, Thursday 12th November.
Specially trained officers are supporting Grace’s family.
Police commenced an investigation into the circumstances around how the girl came to be injured and a 26-year-old man was arrested in connection with the incident.
The man, who has now been arrested on suspicion of murder, remains in police custody.