Read "Overcoming Dyslexia" by Sally Shaywitz. It's great. The most important part of helping dyslexics is helping them learn the code. Many dyslexics guess words and read from context because they have such a hard time sounding words out. Even if they "know" how. It can be hard. It takes practice. Getting a good spelling program designed for dyslexics can be very helpful. And repeated guided reading practice is also important. I would do only a few pages a day or perhaps a chapter at most, this can be tiring. Or even a paragraph. Quit before she is frustrated. Even 5 minutes can help.

Thank you so much for this thread. I just got the 1st grade level set and my daughter read the first 56 pages in one day completely fluently which, for her was a complete miracle. She loves them! Yay.

I think the AOPS Number Theory book is the easiest of the 4 intro books and might be a good place to start.