Welcome to NeuroTalk.

When a backwards fall impacts the back of the head, the doctors often overlook upper neck injuries than can last a long time. C-1 can become unstable and cause inflammation that interrupts nerve function in the body.

Discipline with head and neck posture is part of the recovery process. Some will get help from a upper cervical chiropractor or physical therapist who can help the upper cervical vertebra stabilize.

It can be a prolonged recovery as the ligaments are slow to strengthen.

btw, I don't think there is any evidence to suggest your daughter is finished recovering. Further recovery will be based on self-care with some help from specialists.