Buy a toe by toe manual from amazon.We use them in our school and have had children progress from being almost non readers to reading at high level 4/5 in a matter of months.Then hopefully your dd will enjoy reading age appropriate materials in a short period of time.
you might try Mortal Chaos books by Matt Dickinson (OUP) - they have very short chapters so whilst the writing itself does not specifically cater for dyslexics they are relatively east to read and have an interest level is ideal for a 12 year old. The new teen costa winner - Maggot Moon is by Sally Gardner who has dyslexia. Its interesting reading her bio and might provide some inspiration. I am currently reading and reviewing it for my website www.booksteensandmagazines.com.