This has reminded me that my DD stood up from the dining table and went and wrote my name on the blackboard at about 2.5yrs old, she had a prolonged phase at 3.5-4 of walking around with a little pad and writing one word, tearing it off and leaving it behind, our house was full of little bits of paper. She didn't start to learn to read until 4.5, and took a year to progress to chapter books. And she has tracking problems, glasses help quite significantly.