I applaud your efforts to work with a struggling reader. Keep in mind, that dyslexia is usually not diagnosed officially until after the first grade as many young readers will mix up or reverse letters when reading and writing.
To help strengthen skills with reading and writing try these websites and link:
I had dyslexia at that age. I went to a reading program at my school at the time. They repitiously with the writing on a slighly rough surface back and forth saying the letter and the sound back and forth.. Then words... Also I have seen the Leap frog letter factory which was also helpful for my son.