Hi
I have been on Accutane too when i was 15. Im male tho. I was on it for 6 months on high dosage (cant remember exact dosage).
Hair that i shed because of Accutane (not much) grew back in like half year, so for me it wasn't permament. My friend that also took accutane longer and higher dosage than me got hes hair back thicker in couple months. Neither of us had permament hairloss from it and we both recovered completely.
As someone said already.. theres no cure for Accutane hairloss. It just grows back in time or in some rare cases not.
My suggestions for your daughter would be:
-Relax, be patient and try not to think about it
-Vitamin supplement. Especially Biotin supplement.
-Sleep well
-Healthy food (eat lots of protein, vegetables, fruits, drink water etc..)
-Sports
-Treat your hair gently (avoid ponytail, air brush, styling products, harsh shampoos)
Thats all i know, but you can check more from google "how to make your hair grow faster". Theres alots of info about it.
DO NOT give her Rogaine. thats not good for 14 year old girl and would really just make things worse. It would just cause more shedding.
Hope it helps