Just keep sharing books with her. Point to the words as you read. Show her which way round the book goes and how we turn pages int he right order, from front to back. Look at the pictures and try and work out what the story may be about. During or after reading talk about what the story was about, what she liked and didn't like, etc.
The above are all very important pre reading skills and need to come befoe actual reading skills.
Then look at letters. Look at a phonics based system and introduce letter sounds. Find the letters in books or on paper - can you find an a, etc. Point to a letter and reeat the sound it makes (NOT the letter name). Point them out on day to day activities such as when shopping, when in the car. Play I spy games using the letter sounds.
Then look at blending those sounds with VC words- a/t say them faster together to make at, etc.
Then move onto CVC words such at cat, dot, etc. Find the words in her books.
IMO you do not need any special resources bar normal books, pen and paper.
And no, early or late reading doesn't have a bearing on the general intelligence of a child.