The child has been charged with two counts of murder and two counts of attempted murder.
TVP also said they arrested a 53-year-old man and a 40-year-old woman on Thursday in connection with the double murder.
On 19 October, 17-year-olds Dom Ansah and Ben Gillham-Rice were stabbed, one in the chest and the other in the back, at a birthday party in Archford Croft, Emerson Valley at around midnight. Two more people were injured that day and taken to hospital.
There are also other people involved in the case, including a man in his twenties that was arrested on suspicion of conspiracy to murder and released under investigation.
The police believe it was a deliberate assault.