Have you asked her at all if at any point before you touched her hair if she has done any home hair color? or what shampoos and conditioners she uses..?? It has been my exp if they have played for yrs and yrs with home hair color... That it builds up extreme resistance against professional colors causing conflicts such as you have explained.... and or if she has done over and over semi permanent colors... It could have stained the hair so bad...that it is not allowing anything to change....

 

??? It could be?

Hope it helps maybe?