My daughter has been suffering from acne since she was 9. She is 13 now, and her acne is moderate to severe. She started breaking out a lot on her forehead, while the rest of her skin looked fine. Her forehead was practically covered in red bumps. A few years later, it went away, but now she has severe acne on her back, and cheeks. We've tried several treatments, but with little success. What is the best solution? Should we resort to accutane?
I can sympathize. My 13-year-old also started developing acne at a young age (11). Have you tried the Acne.Org Regimen? We've been using this treatment since October when his skin entered the moderate range and while things aren't perfect (mainly due to being 13 years old and not always consistent with it) it's been keeping his acne under control so we are very pleased. His forehead is completely clear, while his cheeks tend to break out periodically, which is no biggie...his acne is comparable to his peers. His main problem at this point is red marks from old acne, but the Acne.Org AHA+ is really helping. Now you can hardly tell he had acne on his forehead (where he broke out first like your daughter). The cheeks have a few pimples but lots of red marks still so it'll probably take several more months to clear these up. If you haven't tried it, I highly recommend!
Good luck with whatever you decide, and best wishes to your daughter as she finds her clear-skin solution! 
That's exactly what I had. I ended up with PCOS, high testosterone.
Consider getting her off dairy, especially milk, see if anything happens. Dairy has a ton of natural hormones in it that can worsen hormonal issues. It was my worse enemy. Sugar intake is another thing to consider if the dairy doesn't make a difference. Prescription Duac topical cream with a very light cleanser and plain moisturizer can do wonders. The AHA is good too, a BHA product is good for unclogging pores as well but I still highly recommend Duac. Get her away from the store brand, harsh cleansers and products. I know duac has BP but it's more just drying.