Count this as another vote in favor of "do nothing." Just keep reading to her to keep her love of books alive, and the rest usually takes care of itself.
My DD was 5 and we knew she could read, but she refused to demonstrate it. Looking back, it seems like perfectionism was getting in her way, because she was afraid of making a mistake. Anyway, I finally coaxed her past it. I told her how very far ahead she was at her age compared to where I was at the same age, and ticked off a number of points. Then I told her the one place where I had been ahead of her, because I had been reading books to my mom when I was 4. Later that week, she read a book to her mom. Less than a month after that, she was reading aloud to her pre-K class.
