PREDNISONE CAN cause hair loss. I know of several people with CF that have had hair loss issues while on prednisone. The good thing is it tends to stop when the prednisone is stopped.
I also have mild issues with hairloss when I am on prednisone. For me it isn't so bothersome because I have a ton of hair and only typically brush/comb it once a day (after showering) because it is curly and brushes and curly hair don't mix well.
Anyway besides the point. Yes your daughters meds could be causing it since she is taking prednisone it is likely. Also like others have said though have her vitamin levels checked because that could also be exacerbating the situation.
Good Luck,
Lindsey