Time to bloom
Everything in it's own time - yes?
That is especially true of children.
They will learn that skill exactly when they are ready to and not on your fabricated schedule.

We don't rush up to a rose bud and because it is August, pull each petal open, forcing the flower to bloom. That doesn't work. Well it won't work on our children either!
Nowhere is it written what age your unique child will want to read or write or tap-dance.
Bear in mind that even if your reference "the experts" and their "bell curves" you still won't know when it is right for your child.

Have faith!