hi there zoe,
I'm afraid to say, there's not alot you can do to fix her hair. You could try a deep conditoning treatment, but i doubt it'll be sucsessful. GHD's are well known (if you ask any reputable hairstilist) to be very bad for hair. It's okay for short but if you have long hair GHD's are a real no-no.
My advice is if she still want's it long, go for some good quality hair extensions. Take these to a salon and get them to cut ALL of her damaged hair off ((Otherwise new hair will be just as bad)) and then get it cut into a style that makes the hair extensions look like part of her hair.
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