Your daughter suffered a concussion that may have been made a little bit worse if her system was still under stress from the shingles.

Correct me if I am wrong but I assume your daughter got the chicken pox vaccine when she was younger. This likely was the source of the shingles virus. If so, her immune system is weak. Studies show that people who get the chicken pox vaccine are more prone to getting shingles at earlier ages than those who actuality got the chicken pox illness.

If your daughter has a weak immune system, she might tend to have a relapse of concussion symptoms when she is ill as the illness with take her system more that with others.

The carpet over the concrete does not provide much protection. It would have to have a very dense pad to make much of a difference. 1/8th inch of shock absorption will lessen impact forces by 50%. 1/4 inch of shock absorption will reduce impact forces by 75%. But, this shock absorption material will need to be very dense, not like the normal carpet pad.

I ran the numbers years ago because I only fell 8 inches onto a hard surface. The impact force was about 64 G's with 1/8th inch of deformation for cushioning.

Puberty is a sensitive time to get a concussion. The hormones can throw the concussed person for a loop.

Your niece needs to find a new neurologist. The MRI's will not show anything from a concussion unless she has access to a high Tesla MRI of 6 or 7 Tesla or higher. Normal MRI's are usually only 1 to 1.5 Tesla. They can show a 1 to 2 millimeter object at best. A CT will show a brain bleed better than an MRI.

With a concussion that causes a small brain bleed, the optimum time for a CT is on the third day. Earlier and it will not show up. Later and the body will have started to absorb it and move healthy brain tissue into the spot.

I would not worry about the shingles. Mentioning it to a doctor will likely be counter-productive. Just having it entered in her medical record is all she needs.

My best to your niece.