Hi there...I know it has to be so upsetting to see your daughter go through something like this.  Being the mother of four daughters and three son AND now 14 grandchildren...all going though those teen years..I really do understand.  There are wonderful medications in pill form, that can clear up the acne so quickly you will be amazed.  I had a sweet nephew that went though it so badly that my heart ached for him.  My brother and his wife got treatment for him...and in just a few months, perhaps less..it all cleared up and he looked like a different person.  This does not always go away by itself, as you can see from different peoples terrible scars.  GET help...the treatment may not be cheap...but your sweet daughter will be grateful and happier.  These teen years are hard enough without the added stress of something like this.  Good luck to you.  
Grandma Duffy :)