Hmmm, let’s see. I believe they each started the Primer when they were 6. My son just turned 9 and is getting ready to start the 3rd reader, which is the 4th book. My dd is 8 and starting the 2nd reader which is the 3rd book.
I warn you, they’ll finish early because if they are like mine, they won’t stick to the one sleciton given to them, but keep going!
Rachel