Elizabeth Bell from East Gordon was struck by the vehicle, last Wednesday, just after 8am on the A6105.
She was airlifted to the Royal Infirmary of Edinburgh.
Her condition at the time was described as ‘critical’, and sadly she died on Wednesday, 7 February, 2024.
Council chief executive David Robertson offered his "deepest sympathies and condolences" following the child's death.
“Our thoughts are with her family, friends and neighbours at this time.
“The Council is cooperating fully with ongoing investigations into the circumstances of this tragic incident. We are providing support to staff involved and support is also in place for pupils and staff at relevant schools.
“As police enquiries are ongoing, we are unable to comment further at this time.”
Police are appealing for information about the crash, which happened near a junction with an unclassified local road.
Sergeant Dom Doyle said: “Our thoughts are with Elizabeth’s family and they have asked for privacy at this very difficult time.
“Inquiries are ongoing and we are asking anyone who has not already spoken to officers and can assist with our investigation to get in touch.”
Anyone with information is asked to call Police Scotland on 101, quoting incident number 0574 of January 31.