Glad that yr gf is going to NSC. It's important let doctor/dermatologist determine the true cause of her hair loss.
Just to share my experience:
If they recommend Minoxidil (usually for aged related baldness) for application on scalp, and she experiences itchness or redness on her scalp, she might want to try Biolyn scalp defense shampoo ($38 per bottle from Guardian Pharmacy). Shampoo, massage by combing, and leave on hair for a while before rinsing off.
It takes about 1-3 month for hair loss to slow down. 3-6 month to stop loss and grow more hair. I add Biolyn Scalp Balancing Serum ($6

to the shampoo for more strength.
It has worked well for me for the past two years.
Hope that the cause is found soon, and her hair problem vanished.